Remember, too, that boys and girls need to be told about sex.
When they aren't told the good and truth about it, they feel alienated.
Talk to your son about what it's for and why. If all you tell him is that he's bad, he won't get a grip.
I hope you have a strong, decent male around your son at all times. They desperately need to model on someone. Much more so than girls in my opinion.
I also keep the same view on this serious matter.