I would sit up straight Look at her eyes from a height above her and say... want to give me a headjob?
Tell her to quiet down or ask the flight attendant for a seat change immediately. This old woman is obviously drunk or crazy and sitting even a seat away from her is risky .. lol .. I would make a scene .. I have a habit of doing that when appropriate .. yeah ...
i would give her one of those serious look and yell at her like "get the fuck away" then ill just sit in the front seat this fucking stupid chinese woman told me not to sit behind her when it was empty seats in the subway when i was about to sit down and she was trying to take up like 6 seats. she told ppl there were gonna sit in front of her that are empty seats "i stinky, u want to smell" she literally asked me to move and said "why you sit here, you want to know me" i sat there regardless cause i ddont take shit from ppl and she keeps speaking broken poor immigrant english to people sitting around her then she tap me lightly and i freaked out and told her to "shut the fuck up loudly where people heard me" it pisses me off when ppl that are dirty touch my clothes.
the the flight attendant and tell her the situation, hope they will upgrade your seat or change seats as far away from her as possible.
tbh i would put the headphones on, music to full blast and face the window and hope she doesn't touch me. if she wasn't sitting next to me and i was watching from a slight distance then i would be rofl and hoping it never ends.
i would have demanded a new seat. they'll here complaints from me for bad flying experience if i don't get a new seat.
i think the airlines in US are pretty good about these things; at least, to my experience. I sat beside a mother and child. They weren't obnoxious or anything, they were in fact very nice. But the child was sick and threw up (luckily on his mom and not on me) and it stinks really bad. The stewardess immediately moved me to the front seat. But in the case of the youtube, i'll freaking knock her out if she annoys me.