I'll admit that I was the initial dumbass this morning - if I hadn't spaced it and started out in the wrong seat I would have probably averted the whole scenario (or at least my part in it)
So, I zombie onto the plane this morning and plop down in 3B. I get all of my stuff arranged, look through the movie options on the IFE, decline the pre-departure beverage, etc. As boarding progresses, I realize that I actually sat in 3C - not 3B. I look across the aisle and there is a guy settled in to what should have been my seat.
I got his attention and told him that I had made a mistake, but if he was supposed to be in 3C, I would be happy to switch, or happy to stay since he was settled. He replied that he was actually in 3A (which was currently empty), but I could have that if I wanted. I told him that I much preferred the aisle, and that was why I had chosen that seat, so the window wouldn't work for me. Then he told me that his friend had been upgraded to 1B, and he was sure that his friend wouldn't mind giving up his aisle for a window. No, I said - I don't do bulkheads. His final gambit was "why don't we just stay where we are, if nobody shows for those seats, we will be fine."
I was really starting to get annoyed by his insistence that he was going to stay in that seat. I pointed that there was no way that flight was leaving with 2 empty seats up front (and it didn't), and he was welcome to do what he wanted with the empties, but I intended to sit in the seat indicated on my boarding pass. I had already apologized for the initial inconvenience - though all of the drama would have been averted if he had sat in *his* seat to begin with, regardless of my stupidly sitting on the wrong side of the aisle.
He moved, grudgingly, but he gave me side-eye for the next 4 hours
I normally won't engage, but I went into it thinking that he had done me a favor by taking my seat because I had taken his. I wonder what he would have done if I hadn't messed up, and was in my correct seat when he boarded? He knew that he was supposed to be in a window - would he have just taken some other aisle seat up front?