I got the impression that the term came from cheesecake being really, really rich and slightly sinful but not quite being sex. I can't imagine anyone putting cheesecake in cheesecloth. Mostly cheesecake now refers to airbrush art by Vargas, Olivia, and the nosecones of assorted old aircraft -- the thing is, cheesecake like that is okay, often even great. Poser Cheesecake of Vicki and Stephanie's butts in butt-floss got very old very fast.