On two different flights I was seated in 2F (on US, so you know there's no room to move) and both time my aisle seatmates refused to get up when I had to use the restroom. In fact, they seemed quite bothered that I dared ask them to let me out. In return, I gave them my big Greek a$$. I also made every effort to get up several times on each flight just for fun. Eventually, the female seatmate got a clue and got up. The male, however, did not. It has been said here ad nauseam, but I will say it again: being in F does not mean one has class (said the woman who put her hiney in some strangers' faces...).