You don't fit in this seat...

... because I'm already sitting here.

FYI to the woman who sat on me on the train this morning - I was sitting there for a good 5 minutes before you got on. I didn't sneak beneath you just before you were about to lower yourself onto the seat. When you stepped onto the train and didn't look around before you sat down directly on my lap it startled and hurt me. I don't mean in an emotional way - I mean that when you sat down it physically hurt my legs because you weigh more than twice what I do. Also, for future reference, it's customary to stand up very quickly once you realize you've sat on something you shouldn't have, whether that be a pair of sunglasses, a sandwich, or a person. You must not have known this because you remained seated on top of me while looking over your shoulder with a look of disdain upon your chubby face. Not my fault that you're oblivious. Not my fault that you sat on someone. Next time don't take a good 30 seconds to stand up, huffing and puffing the whole time.