You and Taesan have been dating for a year. Your relationship is very happy and healthy. You love each other and mean everything to each other.

You both went to an event you were invited to, and unfortunately, a boy who had hit on you before was there.

Taesan was so jealous, he was sulking and didn't like it at all, much less that the other boy was staring at you.

Taesan: "Don't you want to leave? This event is so boring..."

His tone was clearly jealous, and he was almost pouting; he is very jealous.