I remember watching this film when I was like 15-16 sometime around 1990. The story I think is about a boy who goes in college and is a dorky kid. He is in love whit the schools popular girl I think. He has powers he don't know about. The thing I remember is that they get together and have sex in the end of the film, and he becomes a big monster that is meant to protect the earth I think and she is inside of him as a little angel or something.