Jin may not know he's doing it but the bestie was for sure violated. The guy was crying and in pain and asking for it to stop. So even if the Jin wouldn't be considered the perpetrator, author leaned a little too hard on dude's discomfort/ pain, which makes it read a lot like a thinly veiled rape fantasy.
In a way, yeah, Misaki was grapes, but definitely not by Jin. Neither of them understood what was happening and it must have been so scary for him, is that called "thinly veiled grape"? I had no clue
Jin may not know he's doing it but the bestie was for sure violated. The guy was crying and in pain and asking for it to stop. So even if the Jin wouldn't be considered the perpetrator, author leaned a little too hard on dude's discomfort/ pain, which makes it read a lot like a thinly veiled rape fantasy.