I don't think that's the case. I think it's just a fetish that he has. Also if he really was an, "evil asshole" I don't think he would've bothered to go out and get drinks with the uke, and he definitely wouldn't have sat still just to listen to the uke complain about his life. He would've BEEN left him after sleeping with him. Also, I think you have to understand that stuff like rape is kinda common in an omegaverse, and usually the end result is the uke and the seme getting together. I'm not trying to justify what he did, but I don't really think you should call him evil, because if he was truly evil the uke wouldn't have invited him out for drinks.
Wtf is wrong with the doctor. If you care about someone why would you wanna see them cry and even get excited about making them cry? He's evil assholle