This time I wasn't asked to change seats, I was about to offer to change seats.
It was a trans-Atlantic flight, so several hours long. When I got to my pre-booked aisle seat, the middle seat was occupied by a very, very tall man. Sitting in the window seat was his petite girlfriend.
People were still milling around getting settled, so I didn't say anything, but I was planning, once we were airborne, to offer the aisle seat to the guy, if his friend would move over and let me have the window seat. I figured he needed the extra leg room.
But then, while things were still in the boarding bustle, with flight attendants running up and down the aisles and people trying to find their seats, the guy started in on the poor flight attendants.
First, he could smell someone smoking a pipe. Now, smoking cigarettes was allowed on planes at the time, but not pipes. The FA told him no one was smoking a pipe. He very rudely insisted someone was, and the FA went off in the direction he pointed to check it out. She returned to tell him that no one was smoking at all on the plane. He swore at her and told her he could smell the smoke.
He flagged down two more FAs and made them check for the illusive pipe smoker. He also demanded something to drink before we took off and swore some more when he was told he'd have to wait until after take off.
By this point, I was sort of cowering in my seat, because he'd been talking to everyone over me, and leaning into my space. And there was no way in heck I was going to be nice to him and give up my aisle seat.
So much for my intentions of trying to do a Good Deed.