Question: What is the name of the character who has a son named Louis and has been played by the same actor since the series' inception?

Context paragraphs:
Zarif Khan: Zarif Khan (also known as Tamale Louie; died 1964) was an Afghan American restaurant owner and investor.  He operated a restaurant, "Louie’s" in Sheridan, Wyoming, which served tamales, hamburgers, and other dishes.  Khan was apprentice to the original owner, a German immigrant named Louis Menge, and kept the restaurant's name after Menge became a farmer in Montana.

Chunky Pandey: Suyash 'Chunky' Pandey (born 26 September 1962) is an Indian film actor who works in Bollywood films.  He has appeared in over 80 movies in a career that has spanned over three decades.  His movies in Hindi were more successful in the period 1987-1992.  After the failure of his Hindi films as lead hero since 1993, his career in Hindi films faded away.  Chunky then worked in Bangladeshi Cinema from 1995 and most of his movies in Bangladesh were successful.  He has been acting as a character actor since 2003 in Hindi films.

Macaulay Culkin: Macaulay Carson Culkin (born August 26, 1980) is an American actor.  He became famous as a child actor for his role as Kevin McCallister in the family comedy "Home Alone" (1990) and its sequel "" (1992).  He is also known for his roles in "Uncle Buck" (1989), "My Girl" (1991), "The Good Son" (1993), "The Pagemaster" (1994), "Richie Rich" (1994), "Party Monster" (2003), and the music video for Michael Jackson's "Black or White".  At the height of his fame, he was regarded as the most successful child actor since Shirley Temple.  Culkin ranked at number two on VH1's list of the "100 Greatest Kid-Stars" and E!'s list of the "50 Greatest Child Stars".

It's Only the End of the World (play): It's Only the End of the World (French: Juste la fin du monde ) is a 1990 French play by Jean-Luc Lagarce.  It is about a character named Louis who returns to his family to announce his terminal illness.

Bubbles (The Wire): Reginald "Bubbles" Cousins is a fictional character on the HBO drama "The Wire", played by actor Andre Royo.  Bubbles is a recovering heroin addict.  His real name is not revealed until a fourth-season episode when he is called "Mr. Cousins" and in the fifth-season premiere when he is called "Reginald".  Bubbles has a son named KeyShawn, who lives with his mother.

Louis F. Gottschalk: Louis Ferdinand Gottschalk (October 7, 1864 – July 15, 1934) was an American composer and conductor born in St. Louis, Missouri.  The son of a Missouri governor, also named Louis, he studied music in Stuttgart, Germany, where his father, a judge, was American consul.  Louis Moreau Gottschalk was his great-uncle.

Exile (Casualty): "Exile" is the thirty-second episode of the twenty-ninth series of the British medical drama "Casualty".  It was written by Kelly Jones, directed by Steve Hughes, and produced by Jonathan Phillips.  "Exile" first aired on 16 May 2015 on BBC One in the United Kingdom.  The plot sees Charlie Fairhead (Derek Thompson) and Connie Beauchamp (Amanda Mealing) travel to Bucharest to help Charlie's son Louis (Gregory Foreman), who has become a heroin addict and is planning on selling his kidney to pay his debts.

Cowboy Stadium: Cowboy Stadium is a 17,610-seat multi-purpose stadium in Lake Charles, Louisiana.  It is home to the McNeese State Cowboys football team, and is affectionately referred to as "The Hole".  It was transformed for the 2008 season to artificial turf.  The playing surface is named Louis Bonnette Field, in honor of McNeese's longtime sports information director.  Louis' son, Matthew, succeeded him in the post and continues to hold it as of July 2016.

Derek Thompson (actor): Derek Thompson (born 4 April 1948) is a Northern Irish actor, most notable for playing Charlie Fairhead in the long-running BBC television medical drama series "Casualty".  Thompson has played the role since the series' inception in 1986.

Sean McNamara (Nip/Tuck): Dr. Sean McNamara is a fictional character on FX Networks' drama series "Nip/Tuck", portrayed by Dylan Walsh.  His character opens the show with the trademark catchphrase, "Tell me what you don't like about yourself."  His partner, Christian Troy, has been his best friend since attending college together at the University of Miami, which is partly why they went into business together.  Sean is portrayed as the more skilled, yet more troubled surgeon, who apparently specializes in craniofacial surgery.  He is often plagued by family distresses involving his wife Julia and son Matt.  The two also have a daughter, Annie, and a newborn son named Conor.

Supporting paragraphs: Exile (Casualty) Derek Thompson (actor)
Answer: Charlie Fairhead