Ok, i confess: I faked it quite often when i was in vanilla relationships. And i did once with my Master, felt bad about it, told him, faced the consequences (which were dire, i might add ) and don't do it again. If it doesn't work, it doesn't. That doesn't mean it's his fault, nor mine. Sometimes it just doesn't work for me. But sex can be great without it ending with an orgasm. Although there's no denying that it's nicer when it does

To general faking and how often it is done by girls and perceived (or rather not perceived) by guys: A couple of years ago there was a satirical (based on facts, tho) show by a German psychologist. In the first half the couples sat side by side, in the second half the woman sat on the left side of the room, the men on the right.
It was then when he asked the guys to hum when they think that their partner had ever faked an orgasm. There was a barely audible hum.
Then he asked the girls to hum, if they had ever faked it. The result was HUMMMM.