I feel not the least bit bothered. It's good to get up. I always get out of my seat to let people in and out. Otherwise it's just too crammed.
The backside/frontside question is a good one. The general rule is that it is impolite to show the backside. BUT there are two reasons this might be viewed differently a) in the USA and b) on an airplane.
a) In the USA there is a certain prudish, puritan culture where the frontside is sexually connotated very strongly and people might feel awkward. They might prefer to have their face in your backside than in your crotch.
b) On airplanes and other situations where there is really not much space, it is safer and uses less space to present them your backside and slide in while holding (not yanking) the seat in front of you. Going in forward in coach almost certainly means you will fall over and that is even more embarrassing.
So in F it would be the frontside method and in C the backside.
I do appreciate it when people get up for me and always do the same for them. In F it might not be necessary, though.
Allan's tip to not always bother the same person when you are in the middle section is a good one. I rarely have to fly in the middle section but have never thought of that before. Thanks.
Till