Let me ask you this, do you think knowing the details of the A helps you in some way? If so, how? I know you wanted him to tell her it meant nothing and he was nuts, but let's be real here. It did mean something. That doesn't mean it was love and for that matter it could've just meant he was angry or disappointed with you. The point is he's at home. Does he want (and is he willing) to do whatever it takes to work it out? If he is, that says alot.
Yes, this is torture and it sux. Apparently the only way out is through the looking glass. The big question there, is what's on the other side.