19. Carla "Hotpants" McCorkle/Stan Pines Theory
This chapter by Prez Cipher
Am I the only one thinking that Carla (from Stan's flashback in "Boyz Crazy") resembles Mabel quite a bit? And am I the only one that has dabbled into the 'maybe' of Stan being the twins' grandfather instead of great-uncle?
Welp, here's my extremely far-fetched theory.
Carla was already a couple months pregnant with Stan's kid (the twins' dad) when she ran off with the hippie, and because she couldn't get ahold of Stan she gave her son to his brother.
This would make Carla the twins' grandmother.
... My apologies, my brain goes into random-theory-with-little-evidence mode when I'm sleep deprived.