I think it's immoral, but in a relatively benign way; I'm not going to actively comdemn anyone for it. The only person you're potentially hurting is yourself (and your partner/future partner). I'd rather people did it than slept around, though.
But how are you even hurting yourself? On what basis is there any physical or emotional 'hurt' involved? At most it could be considered hurtful if done to excess, but that is the same with numerous other things from eating to exercise. It's a healthy sexual expression (as a rule I tend not to take any moral advice on sex, relationships, marriage or children from an organisation with a male hierarchy that never experiences any of these things), and is only considered 'wrong' due to some misplaced guilt.