Yeah...GS has nothing...as usual. Next time, you might consider it even trying...just sayin'...
So, the reason is actually quite simple. I grew up in a very religious household, and I was taught that it was proper to wait until marriage to have sex. I interpreted the "no sex" restriction pretty strictly in college, and told myself that "sex" equaled "sexual intercourse" only, so there was a lot of playing with my girlfriends, but nothing real.
Once I admitted I was an atheist, I realized that the restriction was idiotic, and that was what Amsterdam was for. To purge it from me in grand style.