Heather, You want to keep your response very simple. Go with "I'm sorry you feel that way". Don't put yourself in the hot seat because you aren't the problem. If you ask him what you do to make up for it, he may tell you something and then 2 hours later it won't be the right thing. Don't set yourself up for pretzeling! No matter what you do or don't do right now, it will never be the right thing w/him. He's grasping for straws and none of them will bring him the illusive happiness he's looking for. The last two questions are fixer questions and you don't want to fix him...he's broken, but not by your hand. He's got to fix himself.
I think maybe what's going on w/him right now w/the ow is an EA. EA's are harder to break than PA's because it is on the emotional level and just sitting around talking and doing things together does take their mind off of what they think is wrong w/their spouses, etc. She's most likely a f@ck buddy and they aren't looking at their relationship as an "affair", per se, but friends on a different level than we would consider them to be.
Listen to what he has to say and then sift through the garbage. Don't try to fix him his problems for him...because these are lessons he needs to learn all by his lonesome.
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.
