Definitely talk to him about the emotional side. That sex can lead to babies and that having a baby in your late twenties is ideal biologically, but financially is best after he has his first degree. That the age of the father is just as important as the mother. That if ever wants to be a dad, that taking care of himself physically (avoiding drugs!) is really important. I know it seems like this is too early for that level of talk, but if he is armed with information he can make decisions about his life, instead of just reacting.
Even though you might have had this talk several times before, kids need repetition to learn their lessons, and I can't imagine a more important lesson than this one!
Talk about the fact that a lot of diseases (like herpes and hep C) are still communicable through saliva. There is a vaccine for hep A/B, but he might have had that vaccination already. Also, he needs to get tested on a regular basis because anyone can be a carrier without having any symptoms of many STDs.
Talk to him about the different kinds of rape (not implying he is a rapist! ), such as a sex partner being under the influence or incapacitated in any way is a type of rape (lots of people don't understand that), talk to him about how porn hurts women and girls, talk to him about how taking sexy pictures can hurt women and girls and that as a good guy he has the opportunity to respect women and girls in a unique and important way. He can set the tenor for how women and girls feel about themselves for the rest of their lives by giving them love and respect, even if they suggest something that seems like fun but can hurt them in the end. A good guy can make a big difference in this world! Also explain that coercion is a kind of rape, that you don't have to hold someone down in order for it to be rape, saying that you will fire them if they don't have sex with you, and then having sex, is rape (and civilly actionable and immoral!). And, explain that guys can get raped too and that he doesn't have to have any sexual activity to be cool or popular, that he has the right to pump the breaks. (Maybe a different phrase, these kids don't pump brakes anymore )
It's ok to talk to him about the physical side, like women aren't ready for intercourse until they are wet. Yeah, I know that is a delicate subject. And, he will be grossed out. But, porn mostly shows dry women in little more than rape style intercourse. Even though she says, "oh yeah!" Doesn't mean she is ready.
