Wife is on the prowl

I watched my wife once, about 3 years ago when she was just my girlfriend. She really enjoyed that BBC but vowed it would never happen again, especially now that we are married. Just a week ago she was adamant that she would not cheat and I was ok with it, but we used her large BBC dildo often. Last weekend she decided she is going to take a black lover, with me there, and fuck him often. She has talked with a few but nothing yet.