I think you're taking this pretty far down the slippery slope. Someone who "mashes" up to you by taking advantage of the carriage bouncing and then slips his arm around you without saying anything is very different from someone asking you for directions. I could see the former being a prelude to assault, while the latter wouldn't be.
For the uninformed, assault is "an intentional act by one person that creates an apprehension in another of an imminent harmful or offensive contact."[0]
