This has been bothering me since I cannot remember the name, and I have tried searching it. I know it's an 80's/early 90's "horror" film. Please don't hate, on how little I can remember, I get bits and pieces of it in my head.

Okay so this boy and this guy promise to be friends forever. The boy ends up torturing people/killing them. I can't remember if it's like a cave or something. Anyway, he makes the guy stay there, and says to him "But you promised to be my friend forever".

I will try to remember more details and post it if I can't figure it out. It's bothering me. =/