yeah the ending (where you marry him for love), he becomes too controlling, everything you do is cheating etc etc. He has an affair on you and executes you for adultery.
You can get an 'good' ending with him if you get with Gisette, and have high stats and high immorality (rec for late game when you get pretty much everyone else's boosts), and arrange a political marriage and tell him about Gisette. I actually liked that ending a lot. Idk what that says about me lolololol.