is this rape? bc it doesn’t feel too right

It's rape. Even if Sandeul seems to sober up towards the end and finds enjoyment in it, he's still coerced into doing it in the first place. Even if we ignore the fact that he's drunk both times (which means he's not in the right mind to understand what's happening), he doesn't really consent ever. He just gives up fighting and refusing cuz Stalker Seme is too forceful and keeps pressuring him.