Originally Posted by
bocastephen
No it is not the customer's seat to trade - the proper process is to notify an agent, request to be rebooked in coach so the next person on the upgrade list can be moved up.
I've witnessed this very thing onboard and have spoken up about it on the spot and was supported by the FA (who said "no") and my seatmate, also on the upgrade list with me.
If the purpose of switching out of F is to sit next to a travel companion, what would be the point of this? You'd end up having to give your F seat to the next person on the upgrade list, who in all probability would not be the person sitting next to your travel companion. So then you'd have to try to engineer a seat swap with THAT person (and we all know how folks feel about seat swaps around these parts) and if they say no, then the whole effort is moot. So you end up staying in F and the next person on the upgrade list doesn't get upgraded anyway.