alot of guys will say that you shouldn't hide your boner from a chick..... but I think it's different in HS...
HS girls aren't quite "sexually mature", and they'll prolly get weirded out to see a guy's bulge sticking out of his pants.....
what works for me is my boner usually ends up along one of my legs, I just put my hand in my pocket and push it down so it's not noticeable...... my pockets are usually big enough so that it just looks like I'm putting my hands in my pockets and nothing else
of course the best way to hide it is usually to stuff it under the belt (although it can be a little painful)..... but it's hard to do that with people around
btw, about "thinking about something gross"..... that hardly ever works..... first of all the teenage male erection isn't always induced by sexual arousal, so thinking aobut something else doens't do jack ****...... seocnd of all, when you're horny, evne if you TRY to think of something gross, you'll end up fantasizing about banging the chick in front of you...... so it only makes things worse
I like the pushups idea..... the point is you need to do something to get your blood rushing to every OTHER part of yoru body
..... exercise is the best way to get rid of a boner, because it does just that.....