i cant remember the name

plot:
there is a couple in house, stranger breaks in, stuns the guy, ties him, rapes the girl.
after that he start telling about how he always watched her, wanted her etc, overall showing that he is mentally unstable.
while he was talking, tied boyfriend reaches knife, cut ropes, stab rapist....and then says that he also was stalking that girl (in scholl or university), that she was something like idol, and he was all ugly or smth like that, but in several years he make insane workout (join tennis team ect) to be able to date her, but inside he remain even more crazy than rapist...and the end i forgot.
art was pretty realistic

sorry for poor english