You know this idea is not unrealistic, especially with the Tank update that was added. Depending how you ended the battle with Tank determines his position when you ask him for sex. So I could see this happening with Roushk and love the idea.
Also side note, there was a moment in time in past updates where you could ask Roushk about being locked up. Before you take him to the tribe you have the chance to lock him up and use him as long as you like then take him back to tribe to heal him. I never got to that part before it was removed so I don't know what he says entirely but I can see this being another basis for your idea. It would just mean that it's more restricted to people who put Roushk in prison rather than how the battle ended.