This is a very interesting topic.

The closest thing I did to stealing an upgrade was on a British Airways flight from JFK-LHR earlier this year. I had heard so much about the new Club World seats, my curiosity got the best of me, and I passed through the curtain and sat in the last seat to try it out, not planning on staying more than 10 minutes. Everyone in the cabin was sleeping, and the FAs were in the galley, so I had no problems.

However, the seat was too comfortable and I fell asleep. I slept for about 2 hours, and when I got up, the FA saw me. She wanted to know if I wanted a tour of the upper deck and first class, and took me around to see it. I even brought the captain his fruit plate on the upper deck, with help up the FA, of course!

After my tour, the upper deck FA invited me to stay in one of the Club World seats until the descent. I took him up and the offer, and stayed in Club, but did not take advantage of any food or drink services.