HAHAHAHAHAHA!!!!
You guys crack me up... The reason my friend is to encourage you to go deeper and harder....
No that's crap....
The reason is that you are NOT deep enough or hard enough.....
No.... also crap.........
Damn!!! I hope I'm right........
Wait wait wait....... Maybe it's got something to do with the fact that women can multi orgasm one wave after another and men can't.... or that the clitoris have a HUGE amount more nerve endings crammed into a very tiny little jelly bean than the glans of your penis....
Or is that crap too....
I can think straight when talking about nam-nams.... hehehe