Thank you @MickeyCheeky!

@sarahsweets - thank you!

I found this online about psychopaths:

socially irresponsible behavior
disregarding or violating the rights of others
inability to distinguish between right and wrong
difficulty with showing remorse or empathy
tendency to lie often
manipulating and hurting others
recurring problems with the law
general disregard towards safety and responsibility

The only aspect that does not necessarily apply to him is recurring problems with the law - though he has had several run-ins. He had a run-in with his ex wife along those lines and with me calling the police on him. He has stolen an item while with me at Home Depot.

He may fit this persona in addition to narcissist.

I also wanted to know if his cheating on me was sadistic behavior on his part - it FEELS sadistic.