I remember when I was 16, I was madly in love with my high school Biology teacher. In retrospect, she was not at all attractive, but the inherent power a teacher has over a student is not a thing to EVER be taken advantage of. I have 4 students who are absolutely in love with teacher, and no way in HELL will I ever be caught alone in a room with them. It's cute, it's flattering, and it's utterly wrong!
If this guy REALLY wanted to pursue an actual relationship then he would need to transfer to another school, negotiate with the parents, and I'd also say get his head examined.