Confused beginner - advice please

My wife has been getting friendly with one of her colleagues at work who happens to be a young fit black guy. They've been having the odd take after work, but now she says she wants to fuck him. She's been talking about doing something like this for a while. We look at interracial stuff online, she showed me this site and made me join. I think he told her about it. She says I obviously don't love her if I won't let her fuck this black guy. She will only allow interracial porn in the house now. She jerks me off while we look at pictures of wives getting serviced by big black cocks. My head is spinning, I'm worried she may not stop at one, and I may not be able to satisfy her. But at the same time it really turns me on. What's the best thing to do now?