AITAH for not tipping after overhearing what my waitress said about me?

So this happened last weekend and I’m still thinking about it. My girlfriend thinks I overreacted but honestly I’m not sure.

I went to this local diner by myself around 2pm on Saturday. Nothing fancy, just wanted some pancakes and coffee. The place wasn’t busy at all, maybe 3 other tables occupied. My waitress looked like she was in her early 20s, seemed nice enough when she took my order.

Everything was going fine until I needed to use the bathroom. It’s one of those places where you have to walk past the kitchen area to get there. As I’m walking back to my table, I hear my waitress talking to another server near the kitchen. She’s pointing in my direction and says something like “see that guy over there? Total weirdo vibes. Keeps looking around all nervous and shit. Probably lives in his mom’s basement.”

I froze. Like literally stopped walking. I have social anxiety and yeah, I probably do look around a lot when I’m eating alone because I get uncomfortable. But hearing someone just tear me apart like that when I’d been nothing but polite? That stung.

I went back to my table and finished my food in silence. When she brought the check, she was all smiles again asking if everything was okay. I just paid the exact amount on the bill and left. No tip.

Now here’s where it gets complicated. My girlfriend found out what happened (I told her why I was upset) and she thinks I should have still tipped because “that’s her job and she probably makes like $3 an hour.” She says what the waitress said was wrong but I shouldn’t have taken it out on her paycheck.

But I don’t know man. I tip well usually, like 20% minimum. I’ve worked food service before so I get it. But this felt different. She was making fun of a paying customer for no reason other than I seemed awkward to her. That’s not okay in my book.

Part of me wonders if I should have said something to her directly or asked for a manager, but confrontation makes my anxiety worse. Walking out without tipping felt like the only way I could respond.

Should I have sucked it up and tipped anyway, or was walking out justified?