Ok the first thing I'll say is to go and buy some condoms. Let's assume you're going to have sex at some point, so be prepared.Bringing up the question of sex is fairly simple. When you're alone together, and enjoying each other's company, ask her if she'd like to go a little bit further. You will probably know from her reaction whether she wants to or not. If she seems uncertain, then don't try to push her into. If she wants to wait, then it's your duty as a man to wait until she's ready. And also, try not to seem annoyed or aggrieved if she says no. You're still very young and there's plenty of time left!In the mean time, you can learn about how to make sex last longer using PC muscle relaxation, and also, all about female orgasm with the clitoris.