finally someone with media literacy skills, we can admit these are horrible acts, but as a character he would never do this consciously.
preach
FINALLY! This is what i'm tryna say. This is what most people don't understand. Like, obviously we hate the fact that Jin is in absolutely excruciating agony, but he accepted his fate, he knew what he was in for and he's experienced it before. Matthew is literally in his dream world and as you said, people are allowed to have their dark thoughts and manage to keep them to their selves when they're sober and conscious. Matthew isn't is that conscious OR sober state, he's completely gone within his own mind and when he 'wakes up' hell be completely mortified of what he's done, hell be engulfed in his regret and Jin will in fact make him pay so either way, Matthew will pay the price from both sides.
Y'all are ruthless. We know that 1. Matt was drugged on something DANGEROUS without his consent, 2. He fully believes he's dreaming so he doesn't know what he's doing is genuinely hurting Jin and had consequences and 3. he would NEVER do this sober. People are allowed to have dark thoughts here and there but it's their ability to keep them in check and make sure they treat people with decency, which he has any time he has been in control of himself. Even Jin acknowledges that it's not like him at all to do this and he even cares to not make him feel worse about all of it when he becomes sober because he understands what a shitty situation it is. Rape is rape and it's horrible but Jin is actively trying to avoid hurting him for a reason and he is a victim too.