He watches in front of me?

Men are known to think about more and sometimes differently than women. By your description it seems that he is thinking of as an object rather than a relationship activity and now that he's doing this on his own basically, it's a problem that is now interfering with the relationship. I hesitate to say that it's an obsession at this point (without knowing more,) but it's at least close to that. Your may want to express your views more strongly at this point, before he spends even more of your time doing this. The "logic" is that this is an obsession, but from your point of view it's a hurtful distraction from an important relationship. I hope you can find a way to share your thoughts with him. Good luck!