On s'en balek comes from the French slang expression on s'en bat les couilles, a crude and very common way to say you could not care less. The respelling balek reflects casual internet and texting style, where the phrase became shorthand for total indifference. This recording is credited to Mr Yy under the full title On s'en bat les couilles. Shared as a short soundboard clip, it spread as a ready made French reaction for chats, edits and streams whenever someone wants to dismiss something instantly.