High school kids should limit themselves to hand/mouth stuff. It's a really bad idea to be having sex before 18, IMO. I've done everything but actual sex (I'm 17), and I've gone out of my way not to have sex. I just got out of an over-a-year long relationship, and I'm very happy that I didn't bang my girlfriend. Furthermore, as Predator said, I don't think it's a good idea to have sex before two years-ish/marriage. I know it's different for everyone, but I think that's a good rule of thumb.