Well, maybe you are Worrying about something that is not really that much of a concern. Whatever the case, talk to your wife to the point of exhaustion on this issue. Place some extremely severe limitations on such a situation, should you Both decide to take this step. I would ALWAYS err on the side of the marriage relationship !
No way I would ask my wife to do this if I thought I would lose her and I've said to her I do not mind giving her up for a night as long as she comes home with me. I get she might feel a certain way in bed with a black man but I am a good provider so I have that to offer. And my wife is not doing this under duress, she is genuinely interested in a black man as a sexual partner and that excites me. My wife does not do anything halfway so I know she wants this for herself.