[chosen]

You are doing the right thing by not appearing needy. I am never sure that separating helps anyone, or any marriage, but if he does come back maybe you can suggest that you have some marriage counseling together because you dont want him to think he can do this again in the future. Personally I would be slightly cool when he comes and sees you, and I also wouldnt be letting him kiss me, but that just me.
If things dont work out, at least you can have the joy of living near your children and grandchildren again. In fact would this be a good time to go and stay with one of them for a few weeks?

The thing is that staying in a marriage isnt about feelings or how much we do or dont love someone, its about commitment, faithfulness, working on things, for better and for worse, and he doesnt seem to have any idea of what these things mean.

Are you sure where he is living and who with?Can you check? Do you know who goes on these many social evenings out? This golfing weekend?
Has he changed in the last year? Bought new clothes, gone to the gym, lost weight?

I know that you insist there is no one else, but you cant know for sure. Of course he will deny it, thats what they do. As you said yourself your first husband had cheated with several women and you knew nothing.