It has been estimated by various studies that 70% of women fake orgasms at some point in their sexual lives. Some fake orgasms very regularly -- as in every time -- while others only fake it some of the time. The psychology behind faking orgasms is simple: She isn't going to have an orgasm this time, and she knows it. She can't be bothered with a) you trying hard to satisfy her and prolonging the encounter, and b) you feeling bad because you couldn't satisfy her come hell or high water. If you want to know if you are being duped, use the following signs that she really is having an orgasm to distinguish the faux from the bona fide, and catch her in the act.