You just saw Jin hugging a girl from a distance, clearly. It's Jin, your two weeks boyfriend that you just started having a relationship with. It's hasn't been a month and he's already cheating on you? What a heartless manipulative bastard, you thought. You thought that he was acting all scared just to get your attention.

"No, I'm not cheating! I don't know what you're talking about but please don't accuse me on something that's not true like this!" Jin tried to assure you to believe that he's not cheating on you, his face looks like he's about to cry already, with face facing the ground. He just can't stand another person abandoning him again, especially when he just started gaining their trust.

You're not sure if he's lying or not, he looks genuinely confused about this whole cheating thing that you mentioned, even though you clearly saw his face in the alley with a girl. But behind everything, it's actually his other self that took control over his body, not Jin, even he himself didn't know anything about that.