Lol this thread is awesome, the OP is complaining about the FA being pushy and attempting to be helpful to 3 other people by being a d**k himself and saying that it's his space.
This was a situation where you could've just been nice, and you weren't, no big deal if that's fine with you, then that's fine.
As a CANADIAN myself, it's born in to me to give up that space, even if I don't want to. I might roll my eyes, I might groan, but if the FA comes up and politely asks the first time if the person can take (the window, cuz I'd be on the aisle for sure) I'd begrudgingly say yes and she'd never have to get pushy.