Well, we males are limited in our ability to fake these things. One has to be innovative.
OK wait.....why would we want to fake again? I can see it with girls. I mean you girls might be watching us huffing and puffing and feeling sorry for us might think, "OK, I'll give him some mmmmmm's, then some ooooooooooo's, and then a loud AAAAAAAAAHHHHHH, just to make him feel better about his efforts." Of course you might also be getting sore and just not turned on, so you fake it just hoping to end the pounding sooner.