I see it as, OMW already knows and is infuriated enough by it. So, in him contacting her, she may just get so fed up with the situation that OMW will give OM the boot and just free up OM even more to the WAW.
No idea what OMW knows at this point. W claims that OMW blew up due to W's "innocent" comments on OM's FB wall. If OM spoke to his wife in glowing terms about my W (like the stuff I was hearing from my W) and then OMW saw OM chatting it up on FB with my W it's POSSIBLE that OMW blew up over that. She may not know that anything happened. From her email to W it sounds OM told OMW that my W was chasing him.