OK. How's this? Friday afternoon; in his office (a vehicle showroom-no walls); a calm, dignified, confident voiced me walks in and says "Hi Bxx, Have a moment? I'm demanding that you back away from my wife. This secretive little affair is completely unmanly and the act of a coward. This will be the only warning you get. If I have to tell you anything else, I have your cell number and your address. Any questions?"
Quick and direct.
I will not be visiting my wife while I'm there. Just let it circulate on it's own. I'm doubting he'll be interested in beer night. Or her for that matter. But I'll look into a tail if I can arrange something.
