To love too much is to abuse. It is tantamount to treating someone as an extension, an object, or an instrument of gratification. To expect too much, to denigrate, to ignore - are all modes of abuse. There is physical abuse, verbal abuse, psychological abuse, sexual abuse. The list is long.
Narcissists are masters of abusing surreptitiously.
You have to actually live with one in order to witness the abuse. The bulk of narcissistic behaviours can be traced to this panicky reaction to the remote potential for loss of control. They are obsessive-compulsive in an effort to subdue their physical habitat and render it foreseeable. The narcissist is a solipsist. He carries the whole universe in his mind.