I love this thread!
Anyway . . . If you love somebody . . . What's wrong with having sex? IF you love them. This is the one thing I disagree with the Church on. I mean, back in the day, when there was no formal way to be married, did the people who procreated go to hell? Was THAT sex considered a sin? You can't change it just because a law is created that says THIS is when you're married. So, like I said, when you're in love . . . Go for it.
EDIT: I also want to clear this up - Subtract the use of a condom or any other form of birth control, because that's just saying I want to have sex but not have a kid. When the fact of the matter is, you can avoid getting pregnant because women are only capable of being pregnant 24 - 76 hours out of the month. So . . . Have sex, don't use birth control, and if you get STDs - It's not my problem. Hopefully, however, if you DO decide to have sex before you're married, because of the fact you love the person enough to fuck them, you'll love them enough to stay with them, right? Right, so there's not a BIG risk of spread STDs if my plan works.