There is an irrational perception out there that teenagers might not know that sex is a blast. Perhaps if we only tell them about the nuts and bolts of reproduction they won't figure out that sex is a gigantic party and adults spend an outrageous portion of their lives chasing it... and perhaps not. How one arrives at this position is a bit of a mystery considering that masturbation is a thing that kids do - no parent can possibly have missed that even if they do respond by saying "Don't touch your naughty parts or baby Jesus will cry." Even ignoring that completely though you can't possibly miss the conclusion that sex is on everybody's mind. Look at the magazines in grocery stores, type in any search term into google, or watch any sort of TV show or movie aimed at adults and the constant presence of sex and our insatiable pursuit of it cannot be missed. Teenagers know that we all aren't chasing sex just to make babies!
Orgasms rock. We can't conceal that fact from teenagers no matter how hard we try and we shouldn't try in the first place. Chocolate cake also rocks, as do deep fried Mars bars, candied bacon, and calling in sick to work to play video games. You can't build a good relationship with a temptation by denying the temptation entirely nor can you emphasize good habits when you can't talk about the habit in question. You can call in sick to work to play Mass Effect once a year and it is no problem. You can eat candied bacon once a month and have no worries, or have a slice of chocolate cake every couple days. Orgasms require a slightly different sort of moderation as you can have one every half day or so without issues (that's normal, right?) but other sorts of care and caution are required.
I will say it again: Orgasms rock. The teenagers know this. We can't stop them from desperately pursuing them. All we can do is tell them how best to manage the inherent safety risks anyone chasing orgasms must deal with.