Is this really the best start point? I mean do you really expect to cajole, persuade your wife to do something that she doesn't want to do? This always strikes me as quite voyeuristic, quite self centred. The premise may be, that this would be so thrilling for me, she really should try it. May be the start point should be different. Perhaps you acquaint her with different sexual possibilities? I think stories have a place here, but its sexier, more considerate, to start with the erotic possibilities of sex with someone else. Take a look at the film 5 to 7. That portrays a gallic attitude towards a wife taking a lover. It is frankly chic and probably more accessible, less uncomfortable, to a woman. After that, may be occasional reference to the fact that you don't always see yourself as the competitive or the territorial male. If you have black male friends around you both, build the social contacts and don't act territorial about your wife. That's NOT the same thing as prompting her to wear a mini skirt. Here its the importance of being unearnest. It's important not to see urgent, frantic even about this. I suspect though that this could seem scary? It admits the possibility of relationship and feeling in something she shares with a black guy. That really does threaten the husband psyche. Yet may be its at the heart of cuckold nature, instead of the voyeuristic one. May be, I don't know. Being frank with yourself first, is part of it.