Plane passenger refuses to give up aisle seat on 15-hour flight for an 'older lady with mobility issues.' AITA?

"AITA for not giving up my aisle seat on a 15hr flight for an older lady with mobility issues?"

We were on a 777, and the economy seating configuration was 3-4-3. I was seated in the aisle seat of the bulkhead row in the middle section. Next to me was an older lady, probably in her 60s.

When I first sat down, she apologized and said she needed to get up. I told her it was no problem since there was enough space for her to move without me needing to stand up.

A couple of minutes later, she returned with a flight attendant and asked if I could swap seats with her because she had “mobility issues.” I politely declined because I wanted to keep my aisle seat, and the seat next to her was occupied by a very large woman who was spilling into part of the older lady’s seat.

My thinking was that if the older woman truly had mobility issues, she likely would have been pre-assigned an aisle seat, also there really was plenty of room for her to get out of her seat without me having to move, so it seemed to me that she just didn’t want to sit next to the larger passenger. AITA for refusing to swap?

EDIT:

The flight attendant offered her an aisle seat after I declined to move, but she wanted the extra leg room in the bulkhead row and refused the alternative aisle seat offer, so that to me also seems like she just didn’t want to be seated next to the larger lady.

Here's what top commenters had to say about this one:

Mother_Search3350 said:

Airlines allow people to prebook their seats. She knew she has mobility issues and CHOSE not to book a seat that was comfortable for her and thought she would just force someone else out of their assigned seating. The entitlement is on steroids. You are definitely NTA.

FrozenBearMo said:

NTA - I have to book two seats or fly first class because I have a large frame. Big shoulders, big butt. It’s 23 inches across. I carefully plan and select my seat so I’m not encroaching on anyone, so we can all fly in relative comfort. Old lady can do the same, she was just being cheap and trying to take your seat.

StarryPeachPie said:

NTA. You were courteous, and the offered alternative aisle seat makes it clear her request wasn't about mobility but seating preference. On a 15-hour flight, keeping your chosen seat is completely justifiable.

No_Cockroach4248 said:

NTA, the old lady should just have been honest with the flight attendant instead of coming up with a poor cover story.

Sassypants2306 said:

Just look the flight attendant in the eye. Smile politely. And say "I'll swap seats if my alternative is business class or higher." NTA.

AdEducational1519 said:

NTA. Former Cabin Crew here: People with reduced mobility are usually supposed to be seated on a window seat for safety reasons. In case of an emergency they are the last to get out of the plane to make sure the vast majority of the passengers get evacuated safely.

angelpppetite said:

NTA. She had another aisle seat option and just wanted the better spot. Like, that’s on her. You paid for your seat, and it’s totally fair to keep it. Boundaries matter, even on a plane.