I have politely told him that I do not wish him to continue the A whilst still in the house - he refused to stop seeing her. When I asked him out of respect to wait until he had left the house before taking OW away he again refused and told me that if I tried to stop him he would leave right there and then and he was quite angry in the way he said it, that was at the weekend.
I'm sorry, I didn't explain myself very well in that post. I was responding to your comment that his mom told you to kick him out. Normally in your sitch friends and loved ones will tell you to kick him out, leave him, etc. Michele talks about this in chapter 1 of DB, they're doing that because they think it's healthy for you. But things aren't that simple, kicking him out doesn't suddenly make you feel better and get over him. The point I was trying to make is that if you're trying to work on the M, then tell that to any friends or family that may be telling you that D is the best choice, and ask them to support you in your choice to stand.