I think that if you love someone enough, and I mean like, you'd seriously consider marrying them, having sex with them is ok. The point of the matter is is that you have to know if you get pregnant or something, they'll stick around. Or you'd hope that they would, anyway.
I like... someone I can argue with, but not in a negative way. Someone who can keep up with me. I love being romanced though, not gonna lie.