Plane Stains

when you get put in the middle seat of an airplane with a person on either side of you, and you have to keep your arms by your side with elbows tucked in close for the duration of the flight. causing excessive sweating which results in unsightly armpit sweat stains "plane stains" which you then have to parade around the airport.

"that 18 hour flight to London gave me plane stains something chronic!"