William H. Macy Used to Babysit 'Shameless' Co-Star Joan Cusack and Brother John Cusack (VIDEO)

Have you ever imagined that Hollywood stars all grew up together and interacted even when they were younger, and well before they were famous? Well, in one neighborhood in Chicago, that's exactly what happened.

At least, that's what William H. Macy told Jimmy Fallon on 'Late Night' (Weeknights, 12:37AM ET on NBC).

If it's true -- and he says it's his story and he's sticking to it -- both the Cusacks and the Pivens lived nearby. So while he knew Jeremy Piven, it was at the Cusack household that he had more interactions.

"They would hire me to do light carpentry," he revealed, indicating that a set of shelves he built are still in that house.

"She was a young girl," he said of Joan Cusack. "I think I babysat them one time," meaning her and brother John Cusack. That creates a whole new level of awkward to their very awkward intimate scenes on Showtime's 'Shameless.'

"We're in bed together with several toys," Macy said. "It was awful." He imagined her father spinning in his grave over this turn of events. Though, considering their collective humble beginnings and the tremendous success they've all achieved, he might actually be proud.

Probably a little disturbed, as was anyone who's seen those scenes, but still proud.

Watch the full interview here: