That sounds like something a twelve year old would say.

Are you just like really short or something?

I would've asked for his boss.

Looking much younger than your age is a problem with bartenders. Too bad Jeffrey Epstein died -- he might have liked you ;)

That's when you're completely justified in saying, "I want to speak to your manager."

I feel like this is exaggerated. If you look underage they would of asked for ID and not said “don’t even bother”. You sound like a karren to me.

Why would a 12-yo even have a Driver's License/ID that could prove his age?

Absolutely unprofessional.I'd try and get him fired.

I wonder who's gonna be laughing in 200 years when he's dead and you're still alive...

OP, I feel you. Being someone who is short themselves, there is nothing more annoying than having people assume your age based on height alone. I'd ask to see the manager; report the cashier.