At the age of 15, I was going out with a much older woman (who was clearly going out with me because she was a dirty, dirty biatch. Probably sick by IA's definition).
Was I exploited, manipulated, seduced? Yep?
Did I enjoy it? Hell yeah.
My parents were scandalized, I had a lot of fun, and was lucky not to catch a serious STD.
I remember being totally devastated and messed up when it fell to pieces, but I think that's the nature of teenage relationships. I was seeing someone else 2 weeks later, so it couldn't have been that bad.
@InternetAuthor - I'd agree about the maturity thing. I was an irresponsible lunatic until about the age of 29.
And there's no way I'd allow my daughter to do what I did, because it was awesome, but I'm lucky to have come through unscathed.
In this case, I personally think the problem isn't the age gap, so much as the fact she's a teacher. I know of college lecturers who secretly fuck their students, and although it's not child abuse, it's still very wrong.
There's something about the teacher/student doctor/patient type relationship that shouldn't be violated.