In his excellent post (caution - explicit), Smitty put out a list of what mistakes women make during sex.
In # 43, he / the author says: "Faking orgasms [is wrong]. Just. Don't. By faking (IF he believes you) he thinks he's doing everything right. And if he doesn't know it's not working, he's not going to change it. Starting a vicious cycle of unfulfilling sex which will eventually be very damaging to his ego."
Good point, actually.
On the other hand, I keep hearing that it's better to fake in order to boost his ego, especially when he's put a lot of work and effort in his foreplay.
There simply are times - ususally before a woman's period -, when a woman's libido is just nigh nill. Nothing we can do about it, it's hormones. But why make the men suffer? Why not show him we appreciate what he's doing, even if we don't reach climax?
So what's your opinion?

