The Non-FT in the middle seat...
Three regular possibilities:
1) Excuse me, please, please, would you mind swapping seats with my Husband/Wife/Fiancee/Child who is sitting in set 32B so we could be together, please, sir.... - YES I would mind (although I end up feeling guilty for the rest of the flight).
2) You stand to let them get themselves into their seat, they get comfortably installed, and then remember their crossword in the overhead bin, up again, just after take-off they figure that a pen might be useful... then they need their diary.... and of course when the descent starts back up again to stow it all, not forgetting getting the passport in the middle to fill in the landing card...
Worst of all
3) Mr/s Middle Seat has no book or newspaper or anything else and wants to talk...