It's Always Sunny in Philadelphia: Season 3, Episode 11 - ProjectFreeTV

3 - 11: Dennis Looks Like a Registered Sex Offender

Dennis is mistaken for a recently released child molester; Mac tries to bond with his ex-con father, who can't take his eyes off a creeped-out Dee; and Frank moves out of the apartment he's been sharing with Charlie, and moves in with Charlie's mother.