Would you say something to someone masturbating sitting next to you on a plane?

I would move away from my seat and ask the advice of the flight attendant -- they will ask for a male attendant to help out. They can they ask him to adjust the table or something to make sure the accusation is verified and if it is, the passenger can be charged and you can be moved to another seat.

I think exhibitionists do these things in the hope they get caught and you shouldn't have to . It's illegal and you shouldn't have to tolerate it. But a false accusation won't get very far with the police. However if you're absolutely certain you could call the airline and ask for advice now.

Pour some cold water on him as you get up to move. Of course, the following actions require that 1. the airplane actually provided you with water and 2. the flight is not booked full.

Next time this happens, scream "Help! I need a Federal Air Marshal over here now!"

no way. he didn't have the common courtesy to do it in the bathroom? sicko.

obviously, he likes you. if the feelings are mutual, you might get your own blanket.

No way I am going to speak to that person. I will look at him with disapproval.

no i wouldn't say anything to them but i would tell the flight attendant.

I'd probably just vomit in his lap.

Maybe... keep your fantasies to yourself.

ignore it the best you can,but if it becomes obvious,say "awkward"

probably not unless they were looking at me and doing it lol.