(((((courts)))))

Been thinking a bit... here's my opinion.

I get the feeling that you are assuming he is living with her because he doesn't have a choice. While that might be true, I think it is much more likely wishful thinking. But, I get your thinking.

Here's my question for you. Do you think, deep down, that he doesn't already know that he could come back? I think he does, and he is choosing not to, but you are there, what do you think? IF you REALLY believe he doesn't know it, tell him once. And make it cleat that your non-negotiable boundary is that there will be no contact with her. Tell him it's not an open invitation, you will give him a short time (2 days?) to decide. After that, the invitation is closed, and you will do what is best for you.

On the other hand, if you think he already knows he could come back, then skip that step. Really and truly drop the rope, and do what's you need to do. It's not the end, it might even be what has to happen before he will do anything. At the same time, don't expect that, and don't expect that anything he does or says will be real.

Personally, I think that telling him he can come back right now isn't a great plan, but I really do understand your motivation. I'm just concerned that it will just lead you around in a circle, right back to where you already are.