I just cracked up and instead of immediately saying anything I just opened my partially unzipped hoody, pulled it back until it was obvious that I was a she and not a he, and said 'sorry, nope, but no problem.' I've never seen a kid turn so many different shades of red in my life.
I have to tell this story...
After my mom passed in 1985, I wore her engagement ring to remember her. It fit the fourth finger of my right hand. I had gotten a totally disastrous perm that fried my hair, and one night I chopped off my hair because it felt like dried grass. It was about 2" long.
I was working at a one hour photo lab in a mall, and I had to open, which meant getting there two hours early to get the machines warmed up and the chemistry tested. The mall was open to walkers, even though the stores weren't open. It was common for someone to "rattle the gate" and ask to drop off film early.
Because I had to mix chemistry that morning, I had on an old loose sloppy sweatshirt, as chemistry would make permanent stains if it splashed.
A man in his 50s or 60s ("old" to me back then) rattled the gate and asked to drop off film. I took his film and filled out the envelope.
He saw my ring and asked, "Is that an engagement ring?"
"Yes," I said.
"Who are you engaged to?" (Remember, 1985...)
"Nobody."
"Well, are you a boy or a girl?"
"I'm a girl!"
What I should have said: "Drop your pants. I'll tell you if we match."