When you/your friend does something so stupid, it deserves a punch on the arm.

Briefly, "the realization that each random passerby is living a life as vivid and complex as your own." Originally from the Dictionary of Obscure Sorrows, which has a lot more beautiful neologism definitions like this you might enjoy.

when someone says soemthign so stupid, its beyond giving them a neck.....so u punch them in the arm