As I found out for myself, on 3 separate times. Moving in with an A, them moving in with you, or moving in somewhere new together does not change them for the better.
I saw that when I was legally bound to a lease with then abf, he behaved like he had it made....I was stuck there and he could do, and did just as he pleased.
I suggest instead of wondering about it all as you are, that you just move in with him and let him do whatever he wants....til you get totally sick and tired of him and his damned behavior...and you then move out and get away from him at long last.
I wish you all the luck in the world....you will need it all.
God bless