Question: how i met your mother season 5 episode 15 blonde girl

title: How I Met Your Mother (season 5)
text: No . overall No. in season Title Directed by Written by Original air date Prod . code U.S. viewers ( millions ) 89 `` Definitions '' Pamela Fryman Carter Bays & Craig Thomas September 21 , 2009 ( 2009 - 09 - 21 ) 5ALH01 9.09 When the gang finds out that Barney and Robin are hesitant to define their relationship , Lily forces them to confront their biggest fear ... becoming boyfriend / girlfriend . Meanwhile , Ted is anxious about teaching his first lecture . 90 `` Double Date '' Pamela Fryman Matt Kuhn September 28 , 2009 ( 2009 - 09 - 28 ) 5ALH02 8.73 Ted discovers he had been fixed up with the same woman , seven years earlier . The rest of the gang goes to the Lusty Leopard strip club and see a dancer who looks like Lily . 91 `` Robin 101 '' Pamela Fryman Carter Bays & Craig Thomas October 5 , 2009 ( 2009 - 10 - 05 ) 5ALH03 8.23 When Robin fears that Barney is cheating on her , she soon discovers that he is spending his evenings with Ted learning everything there is to know on how to date her . Marshall gives away a prized possession . 92 `` The Sexless Innkeeper '' Pamela Fryman Kourtney Kang October 12 , 2009 ( 2009 - 10 - 12 ) 5ALH04 8.56 Marshall and Lily desperately try to have a double date with Barney and Robin . A girl falls asleep at Ted 's apartment after meeting him at the bar , making him the `` Sexless Innkeeper '' . 93 5 `` Duel Citizenship '' Pamela Fryman Chuck Tatham October 19 , 2009 ( 2009 - 10 - 19 ) 5ALH05 8.07 Ted proposes a road trip with Marshall to their favorite pizza parlor in Chicago to reminisce their bachelor days , but Lily comes on the trip , spoiling the ' bro ' time . Barney is seeking American citizenship for Robin , but her Canadian traits still remain . 94 6 `` Bagpipes '' Pamela Fryman Robia Rashid November 2 , 2009 ( 2009 - 11 - 02 ) 5ALH06 8.82 Barney , thinking he and Robin are the perfect couple , gives relationship advice to Marshall , which turns out to be a big mistake . Ted and Robin have some noisy neighbours . 95 7 `` The Rough Patch '' Pamela Fryman Chris Harris November 9 , 2009 ( 2009 - 11 - 09 ) 5ALH07 8.82 Ted and Marshall decide to break Barney and Robin up for good after they hit a rough patch in their relationship . When their plan fails , they turn to Lily and she enlists some things to break them up , including Alan Thicke . 96 8 `` The Playbook '' Pamela Fryman Carter Bays & Craig Thomas November 16 , 2009 ( 2009 - 11 - 16 ) 5ALH08 8.44 Barney pulls out all of his greatest tricks to reenter the dating scene after he and Robin break up with the use of the Playbook . 97 9 `` Slapsgiving 2 : Revenge of the Slap '' Pamela Fryman Jamie Rhonheimer November 23 , 2009 ( 2009 - 11 - 23 ) 5ALH09 8.75 The gang celebrates Thanksgiving this year with Lily 's estranged father ( Chris Elliott ) whom she had n't spoken to in three years . Ted and Robin are given the chance to use Marshall 's fourth Slap Bet slap on Barney . 98 10 `` The Window '' Pamela Fryman Joe Kelly December 7 , 2009 ( 2009 - 12 - 07 ) 5ALH11 8.79 Maggie ( JoAnna Garcia ) , a girl next door that Ted has wanted to date for years , has suddenly broken up with her latest boyfriend , giving him and other guys a chance to score with her . 99 11 `` Last Cigarette Ever '' Pamela Fryman Theresa Mulligan Rosenthal December 14 , 2009 ( 2009 - 12 - 14 ) 5ALH10 9.65 After quitting cold turkey , Marshall takes up smoking again , with Lily , Ted , Robin and Barney not far behind . 100 12 `` Girls Versus Suits '' Pamela Fryman Carter Bays & Craig Thomas January 11 , 2010 ( 2010 - 01 - 11 ) 5ALH12 9.78 Ted meets Cindy ( Rachel Bilson ) , a student ( PhD candidate ) who is close to his own age and who happens to be roommates with his future wife . Barney , meanwhile , tries to pick up a hot bartender ( Stacy Keibler ) who hates guys in suits by wearing casual clothes leading to a musical number performed by the entire cast . 101 13 `` Jenkins '' Neil Patrick Harris Greg Malins January 18 , 2010 ( 2010 - 01 - 18 ) 5ALH13 10.52 Marshall finds himself in a quandary as Lily refuses to believe that one of his female colleagues ( Amanda Peet ) kissed him . 102 14 `` Perfect Week '' Pamela Fryman Craig Gerard & Matthew Zinman February 1 , 2010 ( 2010 - 02 - 01 ) 5ALH14 9.28 Barney aims to achieve the perfect week : seven days , seven hook - ups , zero rejections , but a sudden accident changes his way of life . 103 15 `` Rabbit or Duck '' Pamela Fryman Carter Bays & Craig Thomas February 8 , 2010 ( 2010 - 02 - 08 ) 5ALH15 10.00 Ted abdicates responsibility for finding a Valentine 's Day date , and allows Lily and Marshall to `` arrange '' a date for him ; Robin foolishly consents to attend a Valentine 's day party given by her deeply inappropriate co-worker , Don Frank . Barney has a ' magic ' phone but ca n't stop answering it . 104 16 `` Hooked '' Pamela Fryman Kourtney Kang March 1 , 2010 ( 2010 - 03 - 01 ) 5ALH16 10.37 When a beautiful young woman `` hooks '' Ted ( keeping Ted in reserve as backup while she pursues her own dream boyfriend ) , the gang discusses their own experiences both as the one who `` hooks '' and the one on the hook . Guest starring Carrie Underwood as `` Tiffany '' . 105 17 `` Of Course '' Pamela Fryman Matt Kuhn March 8 , 2010 ( 2010 - 03 - 08 ) 5ALH18 10.06 Robin is looking to get back at Barney for being insensitive to her after they broke up , hiring self - help author Anita ( Jennifer Lopez ) to help her out . 106 18 `` Say Cheese '' Pamela Fryman Robia Rashid March 22 , 2010 ( 2010 - 03 - 22 ) 5ALH17 8.37 It is Lily 's 32nd birthday , that Marshall has carefully planned . Ted has to ruin it all by bringing a stranger to the intimate celebration , an incident that causes Lily to drag out the photo albums and review the endless parade of short - timers in Ted 's romantic life . Robin tries to catch Barney in a bad position to take a photograph . 107 19 `` Zoo or False '' Pamela Fryman Stephen Lloyd April 12 , 2010 ( 2010 - 04 - 12 ) 5ALH22 6.88 Marshall gets mugged which leads Lily to think getting a gun is the answer to keeping them safe . Marshall tries to come up with ways to stop her . 108 20 `` Home Wreckers '' Pamela Fryman Chris Harris April 19 , 2010 ( 2010 - 04 - 19 ) 5ALH20 7.71 Ted impulsively buys a dilapidated house after his mother 's wedding . 109 21 `` Twin Beds '' Pamela Fryman Theresa Mulligan Rosenthal May 3 , 2010 ( 2010 - 05 - 03 ) 5ALH19 7.70 Both Ted and Barney jeopardize Robin 's new relationship by professing their love for her . Meanwhile , after spending a weekend sleeping in twin beds , Marshall and Lily decide to get twin beds at home . 110 22 `` Robots Versus Wrestlers '' Rob Greenberg Jamie Rhonheimer May 10 , 2010 ( 2010 - 05 - 10 ) 5ALH21 8.16 Crashing a snobby high - society party allows Ted to show off how pretentiously intellectual he can be . Barney , Marshall , and Lily visit a Robots Vs Wrestlers event . Marshall and Lily make a secret pact to start trying to have a baby if they ever finally see Barney 's doppelgänger . 111 23 `` The Wedding Bride '' Pamela Fryman Stephen Lloyd May 17 , 2010 ( 2010 - 05 - 17 ) 5ALH24 7.69 Ted takes a date , Royce ( Judy Greer ) , to see a new hit movie , The Wedding Bride . However , he recognizes its plot as similar to his relationship with Stella , especially since her fiance , Tony , wrote the screenplay . 112 24 `` Doppelgangers '' Pamela Fryman Carter Bays & Craig Thomas May 24 , 2010 ( 2010 - 05 - 24 ) 5ALH23 8.18 Lily and Marshall make some hard choices upon seeing Barney 's doppelganger . Robin finally gets an offer for her dream job but someone else would end up with it .