Make it a free for all orgy of cucks. And then tell the cucks that the first one to cum has to leave the room for the night. They all have to try and make another cum while not cumming themselves. The cucks are allowed 1 'time out' if they will declare loudly and clearly they are not worthy of their wives by name and beg their Black Bull to fuck their wife by name. If the Black Bull agrees, the cuck will get a 5 minute break to cool down.
Oh yeah, to make thing fair they will all be given matching style panties to wear, each a different color. They must declare loudly which color they want before they get them. I think boyshorts or thongs would be best.