I can't have casual sex because I have long-term relationship goals. Casual sex doesn't fit in that picture. I find it tough enough to deal with the fact that once you reach adulthood, sex tends to come earlier in a relatonship, and you find yourself getting to know someone in bed and out, simultaneously.
I don't want to sleep with someone, and then decide there's something I don't like about them. I never liked to deprive myself of pleasure, however, and if I decide to trust someone I don't like holding back. It was a problem that kept me single for a long time, I dated here and there, but when I met my boyfriend I was glad I'd behaved the way I had.