My H was in shambles too when he realized he would never ever have the lifelong friendship he thought he would with me after he cheated on me and left me.
Honestly, it had no bearing on his affair. In fact, once his GF learned that I would have nothing to do with him she became extremely aggressive and to this day is still very aggressive (two years later).
I think for most WAS they aren't so sad about *who* the friendship is ending with but more they no longer have a solid, stable, loving "crutch" in their life that used to be unconditional.
While this seems unkind if your H was THAT broken up by not having YOU around (instead of *something* stable) he would have ended the affair.
The WAS mindset is fantasy (lifelong friends with spouse, GF, no consequences). The quickest fantasy they drop is the lifelong friends one.. the affair usually "wins".
