I'm glad he came back.
The males are called cocks. I don't know whether you'll have problems with the chickens, but I wouldn't count on a guinea hen using a nest box. They like to get under wood piles and briars and places where no one wants to rummage about. Guineas do take a single mate, so you'd at least know both cocks will be occupied. Most of the horror stories I've heard about mixing guineas and chickens start as a male thing. I just had a rooster kill a young guinea hen. Distract the males, save the populace! Hmm, maybe I'll run for office next go round.
