Well, first of all, sex with someone random isn't all it's cracked up to be. People may say they had a hook up, but most girls need to feel sexual attraction, and in a big way, or the sex will be shitty. And in other instances, she may be attracted to the guy but her body doesn't become sexually aroused because of anxiety and fear -- this will cause the sex to be not so great.
If you have random casual sex with someone you're not involved with? YES you'll regret it. Very much so.
And i'm going to be honest, 17 year old guys and sex? They might as well be the only one having the sex. They couldn't care less about a female's pleasure and have no clue how to satisfy a female at all (believe me, this goes for most men i've known).
Wait until you're with someone you become close to, if you want to have a decent sexual experience eventually. Our first times can be awkward and weird -- it's this way for everyone. HOWEVER, it's not always this way. The truth is, my first sexual experience was great. I was involved with someone and he really got me going sexually. Back in those days there wasn't all the hype about how it was painful, etc... sex isn't supposed to hurt, but when a girl is all worried about it and anxiety-ridden, it isn't going to be all that wonderful. We have to LET GO and be in the moment.
Along with this a 17 year old guy might last ten seconds, so what would you get out of it? And he's not usually going to attend to you with foreplay either. Or help you after he's done, either.
Great sex is about having sex with the same person we are sexually attracted to on an on-going basis. In this case, it gets better with time, because we get to know the person sexually -- if they are WILLING to participate with you. Some guys just are not.
I have been having sex for decades, and in my experience? I have only met two men who were worth my time in bed. THAT IS TWO.
Masturbation can be more satisfying, except, of course, there is no one else there for the physical closeness.
This was my "serious answer". It's all true