Mais putain is an everyday French exclamation that roughly means but damn or but fuck, used when something annoying or unbelievable happens. This stretched putiiiiin version spread as a very short soundboard clip, shared with tags referencing Pommedor, because its 0.9 second length makes it easy to spam in chats and edits. It does not need context or translation to work, the strained shout communicates rage on its own, so it has stayed popular for gaming rage moments, reaction videos and French meme compilations online.