Credit: Ethan Miller/Getty Images for Wet Republic

Simpson sisters unite!

Ashlee Simpson will not tolerate comments about her big sister Jessica's weight.

"It's disgusting that people would say those things," she told Women's Health magazine in its December issue.

"My sister has an incredible body," says the younger Simpson, 25. "I feel sorry for anyone who would judge her, because she's one sexy lady."

Jessica, 29, has frequently been bullied for her fluctuating shape. In October, an NFL cartoon depicted Dallas Cowboys starter Marion Barber snorting, "Man, I still can't believe Tony [Romo] dated Jessica Simpson, even AFTER she blew up bigger than Flozell Adams!" Fox and NFL sponsor Burger King later apologized for the sketch.

And Jessica has been a loyal sister, too: after Ashlee was fired from Melrose Place in late October, Jessica used her Twitter to slam the series. "Who writes this crap?" she wrote of the show's scripts. "Thank God my sister is amazing and got you some press."