What would be your response should a Black man came onto your wife/girlfriend in public, and you witnessed her respond accordingly to his charm? Would you find such moment threatening, or would you welcome the interaction and hope something might prosper out of it?
I actually feel like this might be the best way to make it happen. Have a few black doms briefed on the situation, and tell them to come to the bar we're at getting hammered. Let them grab her ass. Kiss her. Whatever they want, and I pay for drinks.
Then, once she and them start talking, I disappear and make myself scarce. Maybe meet up with a grindr date, or gay brother of one of the doms in the bathroom, in the alley or in their car.
Hopefully, she goes home with them, and I get audio/pics/video throughout the night from the men.