Sasuke was possessive, that was a fact. He couldn't stand the thought of seeing you with another person, someone that isn't part of your family or a close friend. So when some random drunk reached his hand out to touch you, he just couldn't sit still and do nothing.

Long story short, it would have ended up as an attempted murder if you hadn't stopped him from hitting the poor man. It was a cute thought of course, having him as like a personal bodyguard to protect you. But things like these were what made it hard for you to keep your cool. You didn't mind if he was overly protective, but having him lash out on every single person in sight who tries to interact with you was not something to be proud of.

But what could you do? Everything you tell him or scold him about always falls on deaf ears. And with that, the only way he could actually prove to everyone that you belonged to him was by giving visible bite marks all over your body, all for display. It was embarrassing, but all thoughts about embarrassment quickly gets thrown out the window when he presses his lips against your sensitive skin, his hands finding purchase on your hips.

He did it all purely because he wanted to show everyone who you belonged to, but having you squirm and whine underneath him even with minimal touching was enough to make him lose his mind.