I'm not the type to be against forceful sex, I'll have you know. But there's situations in which it annoys me. And this is one of them.
Matthew loves Jin. And now we are experiencing the "I'm so jealous after finding out you had another man before me... Even though I already knew that. But I'm angry mow"-moment. This Trope seriously needs to die.
Even under the influence, especially since he's surprisingly coherent. He might not quite understand that he's truly doing this to Jin, but his anger is fresh, he didn't have it before, amd more than that, it's real.
He found a guy and the first thing they did was fuck on his Initiative. That very experienced guy seemed to want to fuck him in return for acting as his model.
But yeah, NOW you are angry because you "just" found out that he's promiscuous? Get a life.
That's all the way up there with the Trope of the guy chasing his LI basically to the ends of the world, getting hurt by rejection over and over, but then there's this nonsensical "misunderstanding", usually brought on by a single word that's being understood and then blown out of proportion. And suddenly it's the LI that has to run after the other, because they decide to be butthurt and let go of their undying love. When Sometimes, the LI seemingly being straight didn't manage throw them off track.
But as soon as the LI is also interested in the other, we desperately need drama for the story to continue.