Take some freinds with you to stand behind you in silence
Don't ask him "Have a moment" .. If you are there to make a demand you do not ASK him if he has a moment... this sounds way too wishy washy and will NOT scare ANYONE
Telling OM this is the act of a coward is cheasy...
You wait til the busienss is as BUSY as it can be and you tell him
"BACK OFF OF MY WIFE YOU SLEAZY CREEP!!!" and that's IT
walk around him in a circle to put him on the defensive... make him see you are ready to ACT and that he will REGRET PUSHING YOU...
Your speech above does NOT sound at ALL like his continuing the pursuit of your wife will result in anything at all...
YOu want OM to [censored] his PANTS and RUN
Do you honeslty think what you wrote above is going to intimidate anyone?