Why do I keep having dreams where i’m friends with monsters or murderers… :I

and in most cases end up marrying those same monsters or murderers… Like last night I had a dream that I was friends with purple guy from fnaf…and we were like super huggy and all smiles and went on adventures together and he even saved my life a few times. But I knew he was a killer and he knew that I knew, but that didn’t seem to matter to us .-. 
It’s just something I can’t stop thinking about at the moment because i’m just like…‘why did that happen…?’