I'm not sure you can have a real relationship with your mom in there? It reminded me of a story my stepmother told me about when she was dating her first husband and he came down to my grandparents' beach cottage as a "surprise" only there weren't enough beds, the house was full so my stepmother and he slept in the same bed. . . with my grandmother inbetween! LOL; was the 1930's.

It sounds a little bit like he's using your mom as a means of not having to get closer to you or let you get to him?