"Family Guy" and "The Simpsons" are drawing criticism over a trailer released this summer promoting a crossover episode.

The 30-second trailer, which aired on FOX, features characters Bart Simpson and Stewie Griffin engaging in a classic "Simpsons" gag where Bart calls Moe's Tavern and tricks the bartender into asking for "Lee-Kee Bum." Stewie follows it up with his own prank, saying that Moe's sister is being raped.

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That rape joke has created a furor on the Internet with women's groups and anti-violence advocates.

CBS News quoted a spokeswoman for the Washington-based Rape, Abuse and Incest National Network, who criticized the positioning of the joke.

Both animated comedies have been hits for FOX over the years. The episode will air Sunday.