I Ruined My Shift by Refusing to Serve the New Regular Who's Actually Kind of Nice

So, there’s this new regular at my coffee shop. I know it might sound a bit silly since we’re in the business of serving people, but let me explain why I can’t stand them. They come in every day around lunchtime and order exactly the same drink: a medium Americano with two sugars and no room for cream. The funny thing is, they used to be friendly enough when they first started coming in. They’d smile, nod at us as if we were old friends from school. But lately, it’s like they’ve turned into this cold, unapproachable persona. Now, I know what you’re thinking: how can someone change so quickly? Well, here’s the thing: this person started giving me these weird looks whenever I try to make small talk or when they think no one is looking. It’s almost as if they’re sizing me up and judging me behind my back. Yesterday was particularly bad. They came in at their usual time, ordered their usual drink, and instead of waiting like a regular would for us to pour it into the cup, they started counting the seconds out loud. Imagine hearing “One thousand one... One thousand two...” over and over again until I finally finished making their drink. I couldn’t take it anymore. I felt my patience wearing thin with every second that passed. The more they counted down, the angrier I got. So, when they asked for a refill on their already empty cup, I snapped. “Sorry,” I said flatly, “but we’re all out of water to make your Americano. Why don’t you try something else?” Of course, this isn’t how things are supposed to go. I’m not sure what my issue is with them, maybe it’s their stare or the way they count time when I make their drink. But whatever it is, I can’t help but feel that I crossed a line by refusing service and essentially telling them we’re out of something that isn’t true. And here’s where things get really complicated: today at work, another barista told me she overheard the new regular talking about how nice everyone here is. That they like coming in every day and feel welcomed by us. So now I’m left wondering if maybe, just maybe, I’ve been the asshole all along for letting my perception of them influence how I treated them. Did I really ruin their experience at our shop without any real reason besides my own insecurities? It’s not like anyone forced me to be rude, and yet here we are. I’m trying to figure out if this is just a one-off incident or something bigger that needs addressing before it gets worse.