I just found something left over from my recent air travel.

It’s a sanitizing wipe, handed out by the flight attendant to each passenger as we boarded. On one side was the airline brand — United — and on the other, this warning: “For external use only.”

Clearly, that’s only there because United’s legal department insisted. But I couldn’t figure out if the lawyers felt it was necessary to discourage any possible suits by people who would use the wipe for other reasons than to clean their hands, or because there had already been a mishap with someone who thought it was a midair snack.

When I mentioned this to my wife, she reminded me the mouth is not the only place something can be inserted in the human body, particularly for women. I responded by saying that in that case, I’m surprised the lawyers didn’t add another warning: “Not intended for cleaning your cervix.”

At that point, my wife put her earbuds in and didn’t talk to me for the rest of the flight.