You may not know this but with your wife just showing her girlfriend those photos, has most likely put thoughts of them having sex with a black guy. Once they are exposed to it, it’s an image they never forget... and given the right time, the right place and especially the right hot black guy who knows how to seduce a white woman, especially a single girl.. but with those images deep in her mind, there would be very little resistance on her part.. The least your wife has done, is expose it to them and who knows where it will go from there. Again, from what your wife has shown them, the right place, at the right time, and the right black guy...anyone of them would have a very low level of resistance..