It's almost impossible not to laugh at people trying not to laugh

What's the best way to get someone you don't know to laugh? Show them a viral video, if the clip below is anything to go by.

Only three of the 12 participants completed the Fine Brothers's challenge of not laughing at some YouTube classics including Flea Market Montgomery, Pretty much everywhere, it's gonna be hot and Grape lady falls! The best part? Watching their faces as they try.

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