The thing about sneakily touching someone is:
It is almost never sneaky from the point of view of the touch-ee. People generally notice when you touch them.
Sneakiness only keeps the other people in the room from noticing. And that kind of puts a different spin on it.
Fuck you, man, I don’t even know your name, and I definitely don’t know what you thought you were going to get out of repeatedly touching my knee.