AS travelling staff, there is no obligation for me to give up my seat for the convenience of a passenger, only if there are no other seats available on the train as a whole, not just the coach I am in. I once had one ask (well, demand) I vacate the seat I was in as there was no one sat next to me, and he didn't want to sit next to someone (most other double seats in the coach were occupied by at least one person) So I gave up my window seat and sat next to him on the aisle seat. He then demanded I move and told him no. I told him if he didn't want to sit next to someone, he should consider driving, and that as the train was fairly well loaded, he would likely have someone sat next to him anyway from the next stop 10minutes away. He then told me he was going to make a complaint about the incident. Childish.
I dislike the attitude passengers have towards staff when we're travelling. You wouldn't speak to any other passenger the way that you speak to me, so why should you speak to me like that? And if you would, then you need to take a look at yourself.