You have my sympathy. We have a boxroom which houses our PC, he has already been in twice to see what I'm doing, even if I close the door he has started to stick his head in and start asking questions. If I'm on the phone in the lounge he will either pointedly turn the TV up very loud or start chipping in with comments that are really off subject because he only hears one side of the conversation or passes me a note to prompt me to ask this or that. He has a couple of lifelong male friends he can phone and I wouldnt dream of listening in or chipping in.
He has just announced too that he's decided not to return to his weekly group meetings once they recommence (male only cancer survivors). If I speak to any of the neighbours he wants to know, in great detail, what they said. He has started to sit in the same room when my mobile hairdresser (who is also a neighbour) comes to give me a quick trim so no chance of a girly gossip there any more. It reminds me of prison visiting when you're not allowed to be alone.
We used to have a small fibreglass boat on the canal and he would happily spend the day there pottering, reading, snoozing, fishing and nattering to other blokes about engines etc., but he announced recently its on the market now because its "too far to travel to get there & hes now bored with it".
We've been here before when he had no interests outside of the house & started to resent anything I did that didnt involve him and I can see it happening again and frankly I'm dreading it.