Ahhhh, the slow dance. In my mind that is what started it all and yes it was in H.S. Where I lived the school dances were not where the action took place. They were too well chaperoned. We were on notice - there was nothing remotely sexual permitted and parents and school staff enforced it. During slow dances you could be close, even lightly touching each other but no hugging or embracing. I am sure some boys got erections; but, as has been pointed out correctly, at that age a light breeze can produce an erection.
But in the summer, ironically, in order to keep us off the streets and out of trouble, The American Legion kindly made their Hall available on most Saturday nights for us to dance. We supplied the music through homemade cassette tapes with the tunes we really wanted. Adults were around but not really as chaperones - for the most part we were allowed to run the show. Turn down the lights and dance any damn way we wanted. In those days we were semi-civilized. There was no vulgar humping and such, but in the slow dances there was plenty of close frontal contact with rubbing and grinding and it was alright for the guy to put his hand on your behind. And yes I think every guy had a hard-on and occasionally I’m sure someone, to their embarrassment, would cum. But the slow dance was really just the teaser, a preview of coming attractions. Don’t get me wrong, it was great - hormones were flooding my young body, a knee pressed between my legs and I had wet panties. I can remember getting so aroused I could hardly stand it.
The Main Attraction was to come after the dance when we were all primed and ready to go. The older Juniors and all the Seniors had driver’s licenses and somehow they got the use of a car. Once the car was parked in some lonely isolated spot and we were alone, the sky was the limit. Even though it was awkward and cramped and we didn’t know what the f--- we were doing - over time we managed get our clothes out of the way and to touch all the wonderful bases. Eventually, perhaps inevitably, most of us (including myself) did “It”! And I believe the slow dance played a major role. Damn, those were truly amazing days!