But then I'll get a whole thread full of offensive responses like this one:
And you should be grateful that my beliefs about God do define my sexual values (and that there's a computer between us, just in case), because, while I'm not certain of any specific commandments, my religion seems to frown upon forcebly castrating people for such lovely comments.
There's a whole context on my reasoning for keeping it in my pants until marriage (and, on that same note, accepting that if I don't get married I won't have sex at all), so it's not simply a matter of "Don't do it because the big black book said not to" (although, frankly, if someone has any sense of reverence for their god, their god saying not to do something should be all the reason they need not to do it, for much the same reasons why, if a man loves his wife and she asks him not to spend all their money on cigarettes, that should be enough, without him needing a lecture on all the issues attached to smoking and all the other things he could spend money on instead). From a spiritual POV, my body belongs to my spirit, and my spirit belongs to God, so I should use my body in a way that reflects that. Also from a spiritual POV, man and wife are one, and give each other to each other in sex, so in a sense if I have sex with Jane today but marry Jill tomorrow, the sex I've had with Jane is giving something to Jane that Jill was the rightful heir to (heir, for lack of a better word, since I'm not Jill's yet); and in the same vein having sex with someone and then marrying her would be a bit like taking my inheritence from my parents while they're still alive (again, for lack of a better analogy; I certainly don't want to compare a spouse to my parents any more than I have to, eww).
From a less abstract POV,
I simply don't like the idea of putting my tongue or my penis where other penises have been, and I feel it would be hypocritical to be turned off by a girl's sexual history and at the same time go around having sex with whoever I feel like.
I'm always a bit stumped when people ask me this. I just do. When in female company, I wear pants. Seems to do the trick.