RNP, You have to understand that early in his relationship, he will be very attracted to the OW. He will also drop little crumbs to kinda keep you in the picture and at the same time, he will do things, like having the OW's underwear laying around to kinda push you away. I know it sounds crazy, and it is. I would recommend that you not meet at his apartment, nor let him come to your house, but meet at a neutral place. Doing that will also get him wondering what you are doing and at the same time keep you shielded from some of that other stuff.