3 Mulligans

Me: “I’d like a double shot of espresso.”
Her: “So that’s two shots of espresso, right?”

After agreeing with her I realized if I didn’t clarify, then I could expect to be served two single shots. Why was she put in control of my mid-day lift? I should have messed with her by explaining a double shot really meant three shots of espresso, but that one of them was imaginary.