SASHA Grey, the porn star going mainstream, is the star of The Girlfriend Experience. It’s break–out performance in which Sash Gray plays Chelsea a, er, prostitute who gives the “girlfriend experience”, which turns out not to be a row over parking and farting in bed but a show a snack and a shag. The film will be one for lovers: she gets to see an unlikely love story and he gets to pretend he’s not familiar with Grey’s oeuvre…