Returning from Milan to Boston with my boss (and company president/major stockholder) many years ago, before I flew enough to have any kind of status, we changed to Swissair in Zurich. I went shopping and got to the gate late. I was met there by a stern, rigidly disciplinarian woman who informed me "You are late. We have given your seat to another passenger." When I asked "Is there any way I can get on the plane?" she replied, meaning every word of the first part, "Yes, but I am sorry. You will have to fly in first class."

I tried to scrunch down in the seat, look very small, and not meet his eye as my boss walked by on his way to his coach seat.

He knew I had a coach ticket, because he had to sign my travel authorization and expense report. He never asked how I got into first.

The flight was wonderful. Six months later (by genuinely mutual agreement) I wasn't working there any more. I have my own company now. We encourage our travelers to go for free or cheap upgrades any time they can, any way they can. We pay the nominal cost of upgrade coupons, though we won't pay full coach unnecessarily or Delta's usually-exorbitant charges to get an upgradeable non-L fare.