My 2 cents. I have never slept with someone I wasn't in love with, or cheated, but I have been sexualy frustrated plenty of times. I know I've thought about having meaningless sex with people before. But I know sex with someone your are in love with is amazing and that I generally feel closer too them afterwards. The problem comes that men NEED sex. Psycologically AND Physically. Its not just Recreation. If a man goes without orgasm/ejaculation it physically hurts. Especially if the man is arosed frequently with out release. Yes men "have a hand" but its NO substitute for the real thing. And if a man is in a long term relationship and young and not getting the sexual satisfaction he needs he will get tired of his hand and start looking for the real thing elsewhere. If he's not in a relationship he will seek to satisfy the physical need with women he has no emotional connection to. Sex isn't the most important thing in a relationship, but it is important. Meet your man half way if he is too demanding for sex. You shouldn't just let him "use your body" but don't cut him off completely. If he's not sexually happy, he'll start to become unhappy with other things. Even manual (i.e. with hand) and oral (if you are comfortable with it) are able to keep him happy between real sex sessions. He might even appreciate the variety and will appreciate you very much for doing so when you don't feel like real sex. Given the option men prefer sex with someone they love (but not "making love" every time) but if they can't get that they will seek alternatives to satisfy their physical needs.