Rape seems like an extremely unsuitable term for this. A fifteen year old male can be a pre-pubescent squeaker or a physically grown man who has to shave every day. I was on my own at 16 and had an active sex life at 15. If I'd found a 29 year old sex partner at that age, I don't think I would have been able to comprehend what you meant by 'exploited'. A year either way can make a huge difference, but many boys that age are well into the period of having the strongest sex drive they will ever have by far. I think it's wise to have strong rules against HS teachers having sex with their students but rape? It's absurd.