First you need to ask yourself the question: What are you looking for? Just an opportunity to try "doing it", because you are curious, and you want to find out? Or are you looking for something serious and emotional? If you're really serious about making that long distance relationship turn into something meaningful, then forget about the sex part. Seriously, it's not important. I am 25, and I've been a virgin until a few weeks ago, when my girlfriend talked me into doing it with her. ...And we did it... It was nothing special. Useless... To be honest. Some people who haven't done it before think it's everything, but they should realize it's not what love is about. I am at least glad that me and my girlfriend can agree that it's not a part of love. It's just pleasure, and you don't need to be good at it, or even do it at all, to embrace a relationship. So I'd say, go ahead and do what you feel like doing, if you're curious. Just don't ever make the mistake of seeing it as something important you need to be good at. Don't ever mistake it for being a part of love. It's just lust anyway... And by the way, it's not even natural to only fantasize about one person. There is no such thing as "loyalty" when it comes to such things... You can choose only to do that thing with one person, but your mind will always fantasize about a lot of different people.
There's really no way you can say, that sex is a part of love. It's just enjoyment anyways... It's something that you should actually avoid getting used to and addicted to, as it could ruin your relationship, and the way you see your partner.