My wife and I have not been with anyone else since before we were together. I really don't know how to apporach the subject with her and I am 98% sure she wouldn't go for it. And i mean either of us being with anyone else, let alone it being her, and with a black guy, while I watch. In addition, we've been trying for another baby so she's not on the pill. This turns me on even more.
If I could somehow talk her into it, and she'd let me be there, what I would love to do is be very close, even on the bed beside them, then when he pulls out of her for a minute and distracts her with kisses, I would quickly remove his condom without her knowing. Then I'd watch as he fucked her hard and filled her ovulating vagina with his potent black seed.
That's my fantasy, now how can I talk her into it?