treated badly, going back for more

I’m in a loving relationship of 15 years, my partner is kind and sweet, but I don’t feel like he ‘wants’ me, I don’t feel like he’s looking at other women I just don’t think he has that drive.
There’s someone who pursued me for a while and he is also in a relationship, he seems to be no longer interested in me. I have learned now that this was just ‘fun’ to him and he had no intention of leaving his relationship anyway.

But the thing I’m struggling to coach myself on is that he treats me terribly, lies to me, objectifies me, and has a history of doing this with other women. It bothers me a lot that he’s not interested in me, the worse he treats me / the more he objectifies me, the more interested I am. If he was nice to me I don’t think I would be at all interested. I think the switch would flick and I would be bored. I want to be bored of him!

I’m confused… a man treats me terribly and I am all in.
My partner is the only nice, kind partner I have ever had. What is wrong with me?