Eww, I would be really worried about the voyerism. Think of how humiliating it will be for you when he gets caught. (Notice I said WHEN rather than IF.) He is kind of sickening, don't you think? You ought to lose him, and send an anonymous note to a boss at his place of employment, or else now that you know, you have some limited responsibility for it continuing.

By the way, things don't look good for you overall, anyway. He is obviously interested in men.