The niceness and politeness is all a facade - it's false, because he needs people to think well of him and he covers up his abuse by being oh so polite and nice. But that doesn't mean he is IN FACT a nice person. The true him lacks empathy and watched as you melted down without wanting to help the one he supposedly "loves". That in and of itself is a n act of sheer cruelty. His false facade is confusing you, and is clouding you from seeing the real him.. which is a monster inside.