An appropriate response to every and any situation. Originally derived from the the bepis/conk bird meme, it's use has expanded to its current situation given the word's similarity in sound to the word for a man's genitals.
Kevin: Hey, how are you doing. Do you want to go out tonight?
Distorted version of the word penis. Became popular in 2011 as a mispronuciation of the word penis, then used again in popularity in the game undertake.
She thought she saw you wearing a bepis, is that true are you wearing a bepis. -Sans in Undertale