Ice tipping is a game where two or more player each stick an ice cube on the tip of their penis. The player who removes his ice cube first loses. Each player then proceeds to ejaculate on the losers ice cube and the loser then has to ingest the cube

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.