Mistress A'IE and I made a movie along those lines. I will have to dig around and see if I can find as it was some time ago. The name of it is "Meal Ticket." If I can come up with it, I'll pm you and set up a way for you to download it.
To your point, I love the scenario of one dom being kinder to the male slave, perhaps even to the point that the other dom is jealous of the male. It opens up all kinds of interactions, such as one of the dom's punishing the slave even harder or playing mind games with him whenever she has him alone. There is a lot to roll with there.
