Really can relate to the airplane stories. Been there and bought that t-shirt!
I remember one fellow traveler who give me "the look" and while I huddled myself into the smallest space possible whilst traveling across Australia - he promptly fell asleep and started to hog up my seating space!
About the seat belts...I seriously looked for an extension to buy so I wouldn't have to ask but couldn't find them on sale anywhere.
As it was I developed the an alternative plan called "flipping the fat". You get on board first (getting a window seat allocation), wear a big loose t-shirt...flip up the fat apron when no one is watching, extend the belt as far as it can go - breathe in tight and belt up. Then huddle yourself into the contour of the window seat and don't move for the WHOLE flight. An attendant once asked me if I was belted up because he couldn't see the belt because of the fat!


Keep at it Fiona! That bewtter future is waiting for you!
Kim