Teddy is the younger brother of Michael Gavin and uncle to Tommy Gavin. Teddy made a lot of money from gambling, but made even more from modelling for a men's sports magazine during and after his career as a firefighter. Ironically, he mistakes the man who hired him as a model for a loan shark that has come to "collect" on his gambling debts. Although Teddy considers himself a heterosexual, he received oral sex from a transvestite (which he discovered after the fact), and wasn't overly disturbed by sexual advances from a black dwarf. Teddy is arrested at the end of season 2 for the unlawful killing of the drunk driver that had killed Tommy's only son, Connor Gavin. during a para-Lee Harvey Oswald-style execution. Teddy was upbeat about his arrest, and accepted the consequences of his actions. During season 3, Teddy appears to be enjoying his time in prison, and asked that no one try to convince the courts to lessen his sentence. Teddy marries a woman named Ellie in order to become eligible for conjugal visits. Although things worked out at first, Ellie becomes too emotional and is often too upset to sleep with Teddy after Johnny Gavin died. Ellie has a history of becoming attached to prisoners and leaving them after they are released from jail. Teddy sees this as his only way of losing her, and desperately seeks to be released. During the second episode of season 4, Teddy is found not guilty of murder and is released from prison. He discusses this with Ellie hoping that she will leave him, however, she wishes to commit to him. Teddy then lies about having to use the restroom and escapes through the window. He is now hiding out in the home of one of the officers who worked at the prison Teddy was incarcerated in. Teddy then goes on to work at a hospital/hospice for retired military veterans to try to make good. At the end of season 5, Teddy loses his wife Ellie to a drunk driving accident and returns to Tommy's bar, putting the blame on Tommy, and shoots him twice, leaving him dying, however later apologizes to Tommy(who survives), and gets off free. He also serves as Colleens AA sponsor. Teddy walked Colleen down the aisle under Colleen's request.