Question: Why did Addison and Sam decide not to become a couple?
About the article "Private Practice (TV series)", section "Season 3 (2009–10)".

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In the series' first episode, Addison is made to feel unwelcome by the other doctors.
They decide to vote on whether she should be allowed to stay at the practice, but when Addison announces she intends to stay whatever the outcome of their vote, they decide to accept her.
Addison is attracted to Pete Wilder, the practice's alternative medicine specialist.
When Pete stands her up on a date, Addison decides they should be friends and nothing more, and instead accepts a date with Kevin, a police officer she met through work.
In a crossover episode, Addison briefly returns to Seattle Grace to help with a patient whose fetus’s heart is growing outside of its body.
The mother and child both survive the surgery.
She leaves, but not before advising Meredith not to let Derek get away.
In season two, Addison learns from Naomi that the practice is failing financially.
She tells Sam against Naomi's wishes, and he launches a hostile takeover.
Sam's attempt fails but Naomi is made to step down as manager.
Feeling betrayed, Naomi breaks off her friendship with Addison.
Addison inadvertently prompts the staff to vote between Sam and Naomi, and is surprised when instead, she is elected to lead the practice as its director.
Addison's relationship with Kevin is tested when her brother Archer tells Kevin he is not good enough for her.
Addison reassures him, and when Kevin is shot in the line of duty, he moves in with her while he recovers.
The two later break up after Addison kisses Dr. Wyatt Lockhart, a well-respected oncologist, with whom she has been competing professionally.
In another episode, Addison is surprised when Archer begins working for Pacific Wellcare Center, a rival practice.
When he experiences multiple seizures and believes he has a brain tumor, Addison asks Derek to treat him in another crossover episode with "Grey's Anatomy".
Derek discovers he has parasites in his brain, and successfully removes them.
As the second season draws to a close, Dr. Noah Barnes is introduced as St. Ambrose Hospital's cardiothoracic surgeon, with whom Addison shares an attraction.
After discovering that her patient is married to him, Addison decides not to pursue a relationship.
In season three, Addison continues to lead the practice.
Displaying her surgical ability, Addison is able to save colleague Violet Turner and her baby.
Meanwhile, Addison's relationship with Naomi seems to be on the mend, despite the latter's departure to Pacific Wellcare.
Addison's father, "the Captain" comes for a visit and it's revealed that Addison is aware of his multiple affairs behind the back of Bizzy, Addison's mother.
Addison is irate when her father sleeps with Violet and he to calls Bizzy to demand that she tell Addison the truth.
Bizzy visits, and Addison is stunned to see her mother kissing an old friend, Susan.
Addison is shocked when Bizzy reveals she and Susan have been lovers for twenty years.
She explains she was expected to marry the Captain due to their social positions, and it was only after having children that she realized the truth about herself.
Addison tries to handle this revelation as her parents leave, falling into her parents' own habit of acting like nothing is wrong.
Also during Season 3, Addison and Sam start developing feelings for each other.
It is revealed that back in college Sam wanted to ask Addison out, but was too nervous, and he ended up with Naomi.
In episode 7 of Season 3, they share a kiss after a terrifying ordeal when they tried to save a married couple who got into a devastating car accident, the husband badly wounded, and the wife pregnant and trapped in the car.
They kiss again when Addison decided to sleep over at Sam's, hurt and vulnerable after finding her mom and Susan kissing.
When ex-flame Mark Sloan arrives at the practice with his pregnant teenage daughter, he and Addison have sex in her office, and Sam walks in and finds them.
He then shows some jealous tendencies, warning Addison about Mark.
Mark and Addison decide not to get back together.
Addison and Sam grow close, but she decides to put a halt on their developing relationship in the episode Shotgun, worried about the consequences in her relationship with Naomi.
In the episode "Love Bites", Addison revealed that she was in love with Sam and Pete, but she decided to begin a relationship with Pete instead, while Sam was with another doctor, Dr. Vanessa Hoyt.
Despite them being with other people, they still show they harbor feelings for each other, including jealousy when they see the other with their current significant others.
After Sam breaks up with Vanessa, he kisses Addison again, saying he was tired of doing the right thing, and wanted to do the wrong thing.
Although she was with Pete, she kisses Sam back and Pete catches them.
He then tells her if she wants to be with Sam, then she should.
But she stays with Pete.
Naomi then finds out about Sam and Addison's feelings for each other, and she is hurt and ends her friendship with Addison.
In the season finale, Addison has to operate on Maya Bennett, her godchild, who got in a car accident on her way to the hospital to give birth.
A close friend of hers, Dell, later dies of a brain haemorrhage as he was the one driving Maya to St. Ambrose's Hospital.
She and Naomi then make up.
Addison breaks up with Pete, saying he needed to be with Violet.
In the same episode, after some advice from Sheldon, she and Sam finally become a couple.
During the season 4 opener, Sam and Addison's relationship seems to have not worked out, but at the end of the episode they are sharing a bathtub, showing that they are a couple indeed.
In the second episode they debate over whether or not they want to go public with their new-found romance, mainly because of Naomi and how she would react.
Addison ends up telling Naomi, and she doesn't take the news well, but Naomi tries to deal with the fact that her best friend and ex-husband are together and maintained a friendship with Addison.
Addison and Sam's relationship, which Addison dubbed "AddiSam", is shown to be a healthy and steady relationship, as Addison says that Sam is the perfect guy "with no flaws".
Although Addison wants to have children, Sam tells her he's not ready to have more children, as he wants to take time in their romance.
Addison's mother Bizzy returns seeking Addison's help in treating her partner Susan, ill with a tumor.
After Addison and Dr. Rodriguez seem to have cured her cancer, Addison plans Bizzy and Susan's wedding.
After Naomi spots Dr. Rodriguez flirting with Addison, she tells Addison that her and Sam's relationship is becoming serious and real, and that's when Addison usually screws up.
Addison assures Naomi that she doesn't want to ruin it with Sam.
Out of panic, she proposes to Sam.
When she talks to Naomi about it, Naomi is furious with Addison, as she knew it was too early in the relationship and she knew she did it because she was enticed into flirting with Dr. Rodriguez.
After Bizzy and Susan's wedding, Addison tells Sam that she loves him and doesn't want to ruin it with him, and takes the proposal back.
During a dance between the two, Susan faints and she is rushed to the hospital.
They find out that she has become worse, and the tumor has grown back, and Susan dies.
After a heart to heart with her mother Bizzy, Addison finds her mother dead in her hotel room, having committed suicide.
Addison tells The Captain and Archer that their mother committed suicide after the funeral.
She gives Bizzy's eulogy as her mother requested in her will.
Sam and Addison end their relationship and Addison goes on a date with a guy named Jake.
Ultimately, Addison decides to go away with Jake in the season finale but after watching Violet run away from her troubles and Naomi run towards new prospects, she realized she was running as well and that wasn't her.
She turned around and went back to Sam.
The season concluded with her telling Sam that she is still going to want a baby.
At the beginning of season 5, Addison runs into Jake again, after she makes an appointment with the fertility doctor in her plight to have a baby.
After several unsuccessful attempts at becoming pregnant, she adopts a baby boy named Henry in episode 5x19.
In the last episode of season 5 Addison sleeps with Jake after harvesting the organs from Amelia's brainless baby.
They agreed after this encounter he would meet her at her place later to discuss what happened.
When Addison arrives home Sam is there with Henry and he proposes to Addison.
It isn't revealed what she says, but we also see that Jake is on his way with flowers and Chinese food.
In season 6, we find that Addison rejected Sam and is now pursuing a relationship with Jake.
Jake and Addison move in together later in the season and get engaged at the beach house home.
In the finale episode of "Private Practice", Jake and Addison are happily married and beginning the rest of their lives with Henry.
In the conclusion of this series it is revealed that it was all an allusion to a book Violet wrote called "Private Practice."
In the third season, Violet survives from the cliffhanger from season two thanks to Pete, Naomi and Addison.
She gives Pete their baby, Lucas, while she recovers from the ordeal.
Addison and Sam get even closer and develop feelings for each other, but decide not to become a couple because they don't want to hurt Naomi.
Charlotte and Cooper break up, and Dell loses Heather in an explosion which nearly kills Betsey also.am and Naomi's daughter, Maya, gets pregnant and marries the father of her baby, Dink.
Addison and Pete become a couple, which causes Addison to get close to Lucas until Violet wants him back, even going as far as taking Pete to court to get joint custody.
Sheldon starts to fall for Charlotte after they start to sleep together.
In the season finale, Addison and Sam finally get together while Charlotte and Cooper get engaged much to Sheldon's dismay.
Pete and Violet work over their issues, while Dell and Maya get involved in a car accident and the severity of Dell's condition is overlooked.
Dr. Amelia Shepherd, younger sister of Derek Shepherd (Addison's ex-husband) operated on him, having just arrived in town.
She was unable to resuscitate him following heart failure.
Maya survived her operation to save her spinal cord and prevent paralysis while at the same time she gives birth to a girl, who also survives the ordeal. 
Season 3 (2009–10).
In the third season, Violet survives the cliffhanger in season two while she gives her baby Lucas to Pete while she recovers from the ordeal.
Addison and Sam get even closer but decide not to become a couple because they don't want to hurt Naomi, Charlotte and Cooper break up, and Dell loses Heather in an explosion which nearly kills Betsey also.
Addison and Pete become a couple, which causes Addison to get close to Lucas until Violet wants him back even going as far as taking Pete to court to get joint custody.
Sheldon starts to fall for Charlotte after they start to sleep together and Sam and Naomi's daughter, Maya, gets pregnant and marries the father of her baby, Dink.
And Derek Shepherd's sister, Dr. Amelia Shepherd, arrives in town.
In the season finale, Addison and Sam finally get together while Charlotte and Cooper get engaged much to Sheldon's dismay.
Pete and Violet work over their issues, while Dell and Maya get involved in a car accident and the severity of Dell's condition is overlooked while Maya was being attended to in the operating room.
Dr. Amelia Shepherd, younger sister of Derek Shepherd (Addison's ex-husband), operated on him but was unable to resuscitate following Dell's heart failure.
Maya survived her operation to save her spinal cord and prevent paralysis while at the same time she gives birth to a girl, who also survives the ordeal.
Sam met Naomi in medical school at the Columbia University College of Physicians and Surgeons.
The two married and had a daughter, Maya Bennett, now age 15.
Although the couple attempt to present the image of an amicably divorced couple, the post-marital relationship has, at times, been strained.
The reasons for their divorce are unclear.
In The Other Side of This Life, Sam professes to Addison that he had "no good reason" for requesting the divorce.
In the episode, In Which We Meet Addison, a Nice Girl From Somewhere Else, Sam states that he was "unhappy" and wanted Naomi to fight for their relationship.
The couple looked to be headed toward reconciliation.
Sam and Naomi rekindle their sexual relationship in In Which Sam Gets Taken For a Ride, after Sam survives a hostage situation.
Although Sam and Naomi called the conference-room sex a "slip up," the couple sleep together again in In Which Cooper Finds a Port In His Storm.
It appears that Sam and Naomi share joint custody of Maya, although her primary residence may be with Naomi.
In the episode In Which Addison Finds the Magic, Naomi states that Maya had asked to spend the entire week at Sam's home.
Sam and Addison are also friends dating back to medical school.
Sam, Naomi, Addison, Derek and Mark were all medical students at Columbia.
Sam and Addison now live next door to each other in Malibu.
Sam asked Addison out before Naomi when attending Columbia.
It was revealed in season 3, episode 7 of Private Practice that Sam and Addison might be harboring feelings for each other after sharing a kiss at the end of a terrifying ordeal.
They kiss again when Addison decided to sleep over at Sam's, hurt and vulnerable after finding her mom and Susan kissing.
When Mark Sloan comes to the practice for a checkup with his pregnant teen daughter Sloan, Sam catches him and Addison having sex in her office.
Sam is shown to be concerned, as he knows about Mark's playboyish ways, and didn't want Mark to lead Addison on, hinting a bit of jealousy.
Following that, they became closer until Addison put a halt on their developing relationship in "Shotgun," worried about the consequences in her relationship with Naomi for sleeping with Sam.
In "Love Bites," Addison admitted to Pete, with whom she was having comfort sex, that she was in love with Sam, though he is angry and hurt by her rejection at the end of the last episode.
Sam begins seeing a well known doctor, Dr. Vanessa Hoyt, and Addison begins dating Pete.
They still show they harbor feelings for each other, even a hint of jealousy when they see the other with their current significant others.
Vanessa realized that Sam is still in love with Addison when Sam backed Addison up on how to treat a patient and the three surrogate babies she was carrying.
She ends things with Sam.
After she breaks up with Sam, he kisses Addison again, saying he was tired of doing the right thing, and wanted to do the wrong thing.
Although she was with Pete, she kisses Sam back and Pete catches them.
Naomi then finds out about their feelings for each other, and she decides to end her friendship with Addison.
It is revealed that his daughter Maya is pregnant.
Sam deals with this much better than Naomi, even supporting the marriage between Maya and Dink (the father), though he is certainly not pleased with the circumstances.
After Maya and Dell get into a car accident, Addison operates on her to try and save her and her unborn child.
The operation is successful and Maya gives birth to Sam's newborn granddaughter Olivia.
Sam and Addison finally get together in the season 3 finale.
During the season 4 opener Sam and Addison's relationship seem to have not work out, but at the end of the episode they are sharing a bathtub, showing that they are a couple indeed.
In the second episode they debate over whether or not they want to go public with their newfound romance, mainly because of Naomi and how she would react.
Sam urges Addison to tell Naomi about them, which she does, and she doesn't take the news well.
But Naomi trys to deal with the fact that her best friend and ex-husband are together and maintained a friendship with Addison.
Addison and Sam's relationship, which Addison dubbed "AddiSam" is shown to be a healthy and steady relationship, as Addison says that Sam is the perfect guy "with no flaws".
Although Addison wants to have children, Sam tells her he's not ready to have more children, as he wants to take time in their romance.
Addison's mother Bizzy returns seeking Addison's help in treating her partner Susan, ill with a tumor.
After Addison and Dr. Rodriguez seem to have cured her cancer, Addison plans Bizzy and Susan's wedding.
After Naomi spots Dr. Rodriguez flirting with Addison, she tells Addison that her and Sam's relationship is becoming serious and real, and that's when Addison usually screws up.
Addison assures Naomi that she doesn't want to ruin it with Sam.
Out of panic, she proposes to Sam.
He talks to Amelia, telling her that although he didn't want to rule out marriage, it was too early in the relationship, and he knew it didn't feel right. 
The first half of the second season dealt with the practice's financial troubles.
Naomi reveals to Addison that they are in danger of losing the practice due to unpaid debt causing Addison to tell Sam.
This in turn causes a shift within the practice making Addison the new boss.
Adding to the drama was the competition of a new practice, Pacific Wellcare.
This new practice, located within the same building as Oceanside Wellness, was run by Charlotte causing turmoil for her and Cooper.
Another happening within this season is the dynamic between Sam and Naomi who by the finale realize they can no longer be friends as well as the deepening romantic relationship of Cooper and Charlotte.
Addison was romantically linked with Kevin Nelson (played by David Sutcliffe), a police officer, but later realized their relationship was going nowhere.
Towards the end of the season, Addison falls in love with cardiovascular surgeon Noah Barnes, who as it turns out, is married and is expecting his first child.
Matters become more complicated when Addison realizes that Noah's wife is one of her patients.
Archer Montgomery (Grant Show), Addison's playboy brother, also made sporadic appearances causing trouble for her and Naomi.
Archer was found to be with an aggressive brain tumor which was later diagnosed as parasites.
Addison sought the professional help of her ex-husband, Derek Shepherd (Patrick Dempsey).
After Derek successfully saved Archer, Addison discovered he was back to his old tricks cheating on Naomi.
Violet stirred some of her own drama when she began dating Sheldon (Brian Benben), who works for Pacific Wellcare, and Pete.
During the latter half of the season, Violet was found to be pregnant although she did not know who the father of her baby was.
Furthermore, Violet found herself and her unborn baby at the mercy of a psychotic patient bent on taking Violet's baby by any means necessary in the closing moments of the season finale.
Meanwhile, Dell struggled with his own issues caused by his former girlfriend's drug habits and the fight for custody of his daughter Betsey.
Some of the medical cases that caused a stir and tension among the doctors at Private Practice was the issue of abortion (a first for the practice), the sex re-assignment of a newborn, the sexual activity of a 12 year old, the switching of embryos for two mothers-to-be and a young couple who later discovered they were siblings.