I noticed something. I don't think his skill makes them get hot for him. I think it enhances what was already there. If you'll notice one of the panels has her asking about how he is doing while blushing. Also something to note is he never gave a command to her, and his skill is one that makes them follow commands. It says nothing about brainwashing them or changing their feelings, only that they will obey. So i get the feeling that it only works in this way when the girl already has feelings for him to begin with.