This discussion was created from comments split from: College Sex Trends & Data.
I don’t know how to bring it up, but I think it’s good you’re thinking about doing so. I’m not against premarital or casual sex, but contracting an STD stinks, no matter the status of the underlying relationship.
“I don’t know how to bring it up”
The best answer probably lies somewhere in between your approach and mine, then. Both my boys have at one point said, “Oh, mom, you’re not going to give me the Condom Talk again, are you? Enough. I get it!”
The funniest was when one of them was describing a new friend who had asked my son a couple of questions indicating he had some large gaps in his knowledge about sex; the son said to me, “mom, you would have been dying to give this kid the Condom Talk!”
For the record, the Condom Talk is mostly about how to prevent STDs and pregnancy, a little about how to be respectful to yourself and the other person in your choices. And it’s served with a side helping of the Nobody Can Consent When They’re Drunk Discussion. So talking about this stuff wouldn’t be a surprise in our house.
So back to the OP asking advice or insights about how to discuss this with children, directly and nonjudgmentally, the same way you’d discuss any other health issue. If it was something in an article, I might throw out a paraphrase of what the article contained, ask them if that agreed with what they were seeing and let the conversation go from there. As long as we’re not in a public place, both of them might roll their eyes a little but will be fine with talking about just about any subject.
Gee I wonder why LOL, could it be that they fear being accused of being rapists and booted out of college back then? It’s fine with me, the female side might be trending up but if they are hetero they have to find willing guys. It’ll all even out in a year or two now that colleges are being scrutinized and told to behave by the courts. Unintended pregnancy was my biggest concerns when our boys were in college followed by MIPs and drinking underage.I sent them all to college with our lawyer’s number in their contacts…seriously. It was my biggest concern for myself (not MIP because we were 18 and legal) when I was in college during the pre-AIDs days.
Personally I think you just flat out bring it up. As far as condoms and birth control probably every high school boy knows some girl and guy with an unplanned pregnancy, that’s usually a good starting point And drinking yourself stupid is the second easily discussed thing to bring up. Alcohol decreases inhibitions and plenty of kids find themselves in bed with someone they probably wouldn’t do things with if they were sober or they find themselves with their first MIP. After that every college in the country will have a required freshman class about drinking and about hook-up culture. Personally I think a very high percentage of kids manage to get through college without issues so just be straightforward and honest with your kids is my advice.
“Gee I wonder why”
They’re addicted to video games and close themselves in dark rooms for hours upon hours. They’re not getting any sex. 
I’d argue if you’ve waited until your kid is going off to college to have this discussion, you’ve waited way too long.
Well yes but better late than never