I was walking down the hallway at work a couple years ago and noticed two co-workers passing an object back when one remarked "go ahead do it".
Well all I could see was his hand at waist level as he started this back and forth shaking motion.
I couldn't exactly see what was going on, but all I and another employee in the hallway kinda gasped! How rude!.....oh it's just one of those shake flashlights, lol! no I didn't want to try it.