They feel it is their God-given right to beat, abuse, and otherwise threat their partner in whatever method they deem necessary and no one can tell them otherwise.
Then there is the verbally abusive and controlling narcissist - the one who uses emotional abuse as his weapon of choice.
They may appear restless, worried, and/or demonstrate a fake laugh that seems to hide something else.
In extreme cases they may describe sudden outbursts of rage with accompanying violence.
Why should you change your behavior for anyone else?