The Gossip singer Beth Ditto has slammed Angelina Jolie for not being a genuine "bisexual".The plus-sized lesbian rocker remains unconvinced by Angelina's same sex boasts, insisting she wouldn't have started a family with lover Brad Pitt if she was attracted to girls. Beth - whose girlfriend cross-dresses as a man - fumed: "If she were a lesbian, or had lesbian tendencies, she'd be with a woman not a man."Angelina, 32, has always been open about her sexuality and dated former Calvin Klein model Jenny Shimizu for a short time. The pair met while shooting the movie 'Foxfire' in which they played two lovers. Meanwhile, Beth shocked fans at a recent concert by flashing her vagina.The 'Standing in the Way of Control' singer - famed for showing off her ample curves - hitched her skirt up, pulled down her underwear and threw her pants into the stunned crowd at a festival last week.One member of the audience said: "Beth had been putting on an incredible show, and was dancing around the stage when she seemed to get carried away in the moment. She pulled her dress up and quickly took down her panties before hurling them into the throng of fans."