The Double Daddy Issues AU is another insane AU on the TWDG roleplay community on tumblr. Basically in this AU, Nate and Kenny are married and Nick from season 2 is their son (because of family resemblance dontchaknow). Nick's girlfriend is Shel, who's the daughter of Omid and Christa and sister to Molly. So yeah, fucked-up families made up of random characters is basically what that AU is all about.
TWDG is (c) Telltale Games.