Seeing the Simpsons meet the Griffins from Family Guy was undoubtedly going to divide the fans of either show, but now that a rape joke has been thrown into the mix, things aren’t going so well for the crossover episode.

A joke featured in the yet-to-be-aired episode includes the punchline: “your sister’s being raped”, and its drawn some serious criticism.

The line is featured in a scene in which misbehaving son Bart Simpson teaches Family Guy‘s Machiavellian infant Stewie the art of prank phone calls.

Bart calls Moe’s Tavern, the frequent target of such calls, and asks for a patron “last name Keybum, first name Lee”. The tavern’s owner, Moe Szyslak, then asks his patrons: “Do I got a leaky bum?”

Stewie, misunderstanding the structure of prank calls, then redials Moe’s. “Hello, Moe?” Stewie says. “Your sister’s being raped.”

The Parents Television Council is one of the unhappy associations, and have tried to have an open dialogue with Twentieth Century Fox, to no avail.

On the other hand, a spokeswoman for the Washington-based Rape, Abuse and Incest National Network said they did not find the line offensive.

“I think the show is making it clear that rape is not funny by how they are positioning the joke,” Katherine Hull Fliflet said. “It’s my hope that would be the viewers’ take-away.”

Check out the full story on Sydney Morning Herald.