That sums it up, really.

It is fine if they are sitting in the seat waiting for me, as this can be practical, but if they have already taken off shoes, stowed stuff in the seat-back pockets, or the like, then that is just rude.

As a general rule, though, I try to accommodate, unless they are giving me an awful seat or I would be giving up a great one. I would never trade exit row or bulkhead in coach, for instance, but would switch window for aisle or vice versa. I'm not overly sussed as to whether the seat is forward or behind.

Then again, the last time something like this happened, the guy sitting in my seat randomly happened to be my boss (well, boss's boss), traveling with his kids on a Saturday morning flight. He offered his F seat for my coach seat so he could sit with his wife and kids. I calmly mulled the offer, called him a sucker/idiot/something like that, and moved up front, aglow in my selflessness.

I have asked to switch before, but only when I am offering the other person something objectively better - like my aisle or window to someone in a middle seat, or F (well, intra-European J, FWIW) for Y. Never had anyone turn me down, but I would be cool about it if they did.

Sometimes it is just easier if they sit in the seat and wait for you since standing in the aisle is likely to be a problem for other PAX, as long as it is clear that they are just doing it temporarily. So I don't always assume that they are being rude. However, if the person wants me to take a seat further back or not an aisle, I will say no and make them move and at that point I will think they are rude. So if you want to wait for the person to come to their seat, IMO you should always choose to try to change so that you and your companion have the worse seats. I have done this in Y -- I have waited in the worse seat for the PAX (often a middle) and then offered him or her the better seat (an aisle in the front). In J I have never tried to change because I usually fly in J by myself -- the few times I have my daughters did NOT want to sit by me anyway! I have offered to trade with people in J at least once that I can remember, but I think it was a short flight and I really was indifferent.

I have had PAX ask if I would trade aisle for window and I always say no telling them that I get claustrophobic and need to sit up in the front and on the aisle or I will go crazy during the flight (which is actually quite true, I'm often up and down). Just because you have a reason doesn't mean you can get argued out of it, my reason usually works pretty well to silence the person.

I also always try to board early partly because of this issue (and partly because I like to have extra time to get comfortable) and because of a past experience where a GA assigned someone else to my seat -- I always want to be there first. So it has been a long time since someone has asked me to switch seats.

LOL ^

duplicate deleted.

Apparently this person doesn't fly F often, but I would have told the
poacher that YES I DO MIND. I CHOSE MY SEAT WELL IN ADVANCE
FOR A REASON, AND I'D THANK YOU TO KINDLY REMOVE YOURSELF
AND RETURN TO YOUR CORRECT SEAT WHERE YOU BELONG.

Or if you're timid, I'd have the FA do tell them to move their butt to
where they belong.

If they couldn't stand sitting where their family are, they should have either got the rest of the family coach tickets and then arranged themselves a seat in F, or picked separate F seats when they bought their tix.

If someone is already in my seat when I get there I think one of two things:
1. They are rude.
2. They are too stupid to figure out what seat they should be in.

I hate moving seats and can only remember doing it twice, once to let a co-worker on crutches have seat 3B on a RJ so he would have more room (I offered, he didn't ask), and another time I don't know why I moved, but I went back three rows, but still in the aisle.

One time a guy was in my seat in first and wanted to fight me for it! Literally, he asked me if I wanted to fight him for it - and he was big, like 6'4 300 lbs big. I told him I didn't want to fight him, I just wanted to sit in my seat, he reluctantly moved back to his window seat about four rows back - I sat down with a big sigh of relief.

Succinct and to the point, and lazybones should move their @$$
immediately.

Poachers belong in the back of the bus Not in F.

If someone is sitting in my seat, I always kick them out. Theirs is an act of aggression, and they created the situation, so I will be more than happy to make it an uncomfortable and awkward moment for them.

That being said, for the first time ever in my flying experience someone was honest with me about stealing my seat. On my first flight of 2008 on an EMB 135 I had 9A (exit row) and someone was sitting in my seat. I did the usual double check of my boarding pass and he volunteered "am I sitting in your seat"? I said yes and he said, "I was hoping you wouldn't make the flight on time". Thank you for your honesty. I have never come closer to contradicting myself concerning my opening remark.

I will always move if asked, except to a middle seat in coach. But once, I has a bulk head window, and was asked to move so granny could sit with the family. As soon as we we got to altitude, granny put the grandson in that seat. I promptly took my bulkhead seat back.

I was in 1E on IAH-LAS or SEA a year or so ago, and the person in 1F asked if I wanted to trade with his wife in 3F. I actually laughed at that one, and the guy said something to the effect of, "just thought I'd ask."

Last year, I marched up to 3E on a flight to SFO to find the guy assigned to 3F sitting in my seat. I did the "excuse me, I think you're in my seat routine," and the guy claimed that he was mistaken. Unfortunately, I had to offer 2B to the guy so that my friend in 2B could move next to me in 3F and I hated to reward this purportedly "mistaken" individual (who was a Plat, by the way).

Actually I DID sit in the wrong seat in first class the other day. I was taking two flights that day and in the second flight I just went and sat in the seat I had sat in the first flight. I was a little shocked when someone came and asked me why I was sitting in his seat. I think I might have said in 2B and was supposed to sit in 1B, although I can't remember exactly, but the guy I think just thought I was dumb and sat in my seat. So it isn't always being strategic even if you fly a lot. You might just be too tired to pay that much attention.

Almost forgot my "best" seat change request. I was on an ERJ flying DCA to somewhere (probably CLE) in 12A. The flight was about 50% full, and two borderline POS's, a husband and wife, were seated in 12B/C. Just before the door closed, the woman in 12B leaned over, tapped me on the shoulder, and asked if I would be interested in moving to 9A. Her selling point was that "it's still an aisle." I actually was so shocked by the absurdity of the request that I just stared at her for a few seconds before saying (indignantly) "no." She looked offended and said "sorry; just asking."

Can you believe that? It wasn't good enough that she and her husband already were seated next to one another in the exit row; they wanted the entire exit row to themselves so that the husband could spread out in 12B/C and the wife could relax in 12A. And, there were plenty of other empty pairs of B/C seats where one of them could have moved if they wanted more seat width in which to beach themselves.

You said it! My rule is simple - if someone is already sitting in my seat, I boot them out and I don't care what their sob story is. If someone asks nicely, and the other seat is better, I will go for it. If they ask rudely or are demanding, the answer is no.

It's a shame that we need to worry about being shamed publicly by a FA for doing nothing wrong.

If you like an aisle seat, then a window seat is inferior (and vice versa)....even in first class.

I was on a UA HNL-DEN redeye in Y, seated at a bulkhead, aisle E+ seat....which is my favorite seat when flying this equipment in Y. It makes coach almost livable. It was a seat carefully chosen in advance. I had this guy ask me to switch with him to his bulkhead window so he could sit right next to his family. In general I am not a window seat person and I told him no. Window seats make me claustrophobic...especially on an longhaul redeye. He put on a big show. He was in the same row as his family and his 3 or 4 kids...can't remember exactly how many...but it was too many. Of course, the guy made me 'pay for my bad behavior' as he crawled over me the whole night to visit his kids.

Later in the flight, the FA came up to me, apologized for the man's behavior. She gave me a UA skykit and told me to send it in...I received a nice travel credit voucher in the mail for that...mind you, I didn't complain and had asked for nothing. (I have since learned that this often happens when you send in the skykit.)