text: how does a guy really know if she is "faking"? um...its not for me...its for a friend of mine.... usually you can tell if the woman is really turned on or not by noticing her body reactions.  when a woman is about to orgasm she may get a red flush on her chest just below her neck.  her breasts increase in size.   the muscles of her body tense up and when the orgasm come they are suddenly released.   you should also be able to feel the contractions of her vagina if her vaginal muscles are strong enough.   of course she can fake that by squeezing them, but she has to really be trying to fake if she can remember to squeeze her vaginal muscles too.