Originally Posted by Trollheart

This.
More or less.
This is NOT your problem, and you've already done, or tried to do, all you could to sort it. It's now their problem. If he lied, HE lied, not you. If you step in between them they'll probably close ranks and attack you, and nothing good will come of it. It's up to you whether you want to dump him as a friend (I would) but don't get any further involved. It'll just go pear-shaped. You don't want to be responsible for anything that might happen, and if something happens afterwards, without you saying anything, that's not your fault. If he's too chicken**** to admit to her he lied, that's his problem and they have to deal with it. I'm sure you have enough problems of your own without taking on those of a shaky marriage with borderline psychosis involved.

Just step back. Let them deal. The door's that way. Use it. And don't look back.