If your W is so madly in love with you why did she take a call from the OM? I know that sounds very negative but instead of looking at WHY your W took the call you are focusing on how wrong the OM is for calling.

Do the two of you have a transparency plan in place? The OM should be blocked, erased and removed from her life in all ways.

You need to set boundaries with your W and she needs to set them with OM.