The only thing you have to tell him is to back off... you find leverage to show him you CAN make HIS LIFE VERY UNPLEASANT if he don'st go away..

Make sure he TELLS your WIFE he does NOT want ANY CONTACT from HER AGAIN... or she will keep chasing him

A lot of OM do this when confronted.. they agree to back off, but they don't TELL your WIFE that they want out... they get an ego boost from being chased desperately.. its pathetic..

You tell this guy to back off and tell your WIFE to back off too... tell him if SHE doesn't stop calling HIM that YOU will make his life unpleastant and show him you can

Find lots of good leverage