I just want to put my 2 cents in. If he is still seeing OW you should set some boundaries. Having the best of both worlds is NOT an option, but only you know if he should move out or not. If he is still at home, you have a better chance at DBing and seeing results, but the other side of the coin is that he is having his cake and eating too. I had to struggle with that and I choked on my pride and remained at home. I was ready to leave or my W was. It was a weird sitch (still is), about splitting up over a 24 year-old punk. My W has fallen to a maturity level of a 13-year old, and she still acts like one from time to time.
Your H is messed up in the head. He's married to you, you both have little ones at home, I mean c'mon!!! He's acting like a child running around with OW and he still wants sex? Stick to your boundaries! You should not have sex with him whatsoever if he is with OW. You don't really know if they are having it or not, so stick to this rule.
As far as him staying or not, let him make that choice. You should have no guilt in this decision. Let it be all his. Keep DBing......
~Sol
~~~~~~~~~~~~~ Single Dad, and luvin it! ~ Happiness is a state of mind ~