SOLVED. YA 3 English Students/ one dates crazy teacher [s]

[Lookingforabookname]

Published before 2008. Revolves around 3 male High school students in English/British Country. One dates a slightly overweight girl, one dates a teacher who is very forward and forces him to do things he isn't comfortable with and when he tries to break it off she slits her wrist and gets hospitalized. I don't remember about the third guy.

The title of the book is also a British slang term, I think for something like homeless or directionless young people.

[Andria]

Doing It by Melvin Burgess? Three boys, one has an affair with the teacher that ends as you describe.

[Lookingforabookname]

Thats it! Thank you very much.

[Yue]

There is also a TV series based on this book, in case you are interested.... It was called 'Life as We Know It' (the overweight girl was played by Kelly Osbourne)