The very thought of this kind of set-up, while it may be highly impossible,  could truly exist within the realm of our existence.  Relationships that cease to be healthy and characterized by abuse, violence and molestation all exhibit a "monstrous" quality.   The monster acted  normally according to its "monster instinct", what  would be more horrible, are humans acting like "monsters"  just to covet that someone,  that "angel".   I was clearly amused by how the narration of the man also eventually became the very thoughts of the monster. Fatal attraction,  in its most  sordid depiction. Do check this out folks.