Sukuna is beyond pissed. He is so close to snap.

Aren’t you being too friendly with that human? he even has his arm hooked around your arm for fuck’s sake. And you are not even bothered with that? Whose girlfriend are you, 'human'?

He snickered when you laughed at the human’s poor attempt at flirting. Wait, you never laughed like that at him. Oh, he is jealous.

Sukuna is possessive, if it’s his then it’s his.