School Trip
I was on my way to Madrid with my then girlfriend, sophomore year in high school, and we sat together in a row of 2 seats on the far right. To the left there was a middle row of 5 seats and a left row of 3. She surprised me by taking a nap on my lap and then proceeding to pull down my pants and go to town.
This was extremely awkward for me because the chaperone was sitting directly to the left and behind us. I was so damn paranoid the whole time that people could hear or see what was going on. They probably did. It was awesome though. Minus me trying to finagle my way to the lavatory without getting my victory sauce all over the pants I would be in the rest of the flight.
Story credit: Reddit / ThaSpaceMan