The ml doesn’t have any problem with it, it’s his butler and your own interpretation, not his.
True he doesn't openly grunt, but he sure as hell doesn't do it out of pleasure, he basically doesnt give a shit and i think its worse being seen as irrelevant rather than the person openly disliking u
I can assure you he give a shit and he is doing it with pleasure. I can tell because I read the book but you can tell because even in the scan you can totally see his concern about the MC and how he is the most excited one during their intercourse. Just re read the chapter 13, look at his reaction when the MC told him his fingers are good, you’ll see
Honestly cant blame ml for being unenthusiastic about this, its not his fault the mc got his name on his body, and i feel really bad for the mc but we cant expect more from the ml than the loveless intimacy (bro is straight), feel so bad for mc hope he finds happiness and gets to sing the piano again