I captured prisoners. How do i turn them into servants?

Create and defend your dungeon from pesky invaders in this 3D strategy adult game · By
I see, so it has to be at least at "love" instead of "like". that makes sense, however there was one prisoner who's stat was at "like" and when I asked if he would serve, he said yes, yet the game did not register his response. I assume his affirmative response at that level is just a small bug. thank you for the clarification though
Easier way if you have money: