The phrase cuh is casual slang for cousin, used like bro between close friends, and come on cuh works as a mild callout when someone should know better. The short clip, listed as Christopher Smooth, has circulated mainly as a shareable reaction sound rather than as part of a longer song or scene. Its brevity made it easy to drop into gaming edits, sports fails and short form comedy videos, where a single annoyed line can replace a caption. That simple, repeatable use is why it remains a go to reaction.