How do you know a girl is faking?

You cannot tell. This was well illustrated in the famous faking-scene in the movie “When Harry met Sally”. If guys say they can distinguish real from fake it’s big talk. Every woman can make the movements and sounds that spontaneously arise when she becomes excited or comes. Even the contractions of the PC-muscles can easily be imitated. The only way of knowing, is asking her. Don’t do this while she is in the throes of passion or right after love making. Talk about it outside the bedroom, when you’re both relaxed. You can for instance ask if she ever feels pressured to (fake) orgasm. Try to find out if she ever has had a real orgasm, for not all women know how to climax. Even during masturbation it can take time before a girl discovers how her body works. If she knows how to come masturbating, ask how she does it and discover how you can introduce similar stimulation in lovemaking. It will improve your sex life.