The 60's and 70's anti-institutional movements did a lot of damage to the covenant of marriage. We are still feelign those effects even 40 years later. There's even a small movement in the last five to ten years to bring some of the exploratory marriage practices of the 70's back.. this all makes me sick.
I would do what you can to educate your mutual friends... particularly people who were at your WEDDING..
Tell them "you were at our wedding. We are still married.. how you can ALLOW this MAN into your home.. this man is attacking my marriage... I am NOT asking for you to get involved if that is uncomfortable for you.. I am just asking you to ACKNOWLEDGE my MARRIAGE until I am divorced please.. and you do this by NOT being involved iwht OM or my wife at all ..."