This may be the ultimate burn! In a hysterical mash-up video that is now going viral, comedian Louis C.K. unknowingly disses his 'American Hustle' co-star Bradley Cooper back in a 2008 interview. At the time, the comedian claimed that the aspiring actors in the 'Inside the Actors Studio' audience who ask questions to the likes of Sean Penn never become famous themselves. Little did he know that Bradley Cooper had done just that -- and now look at him!

"It always occurs to me, you know when an actor stands up in the audience and says, 'I'm an actor, what can I do?' and asks Sean Penn or whoever. 'What can I do to reach your level, or whatever.'  And you just want to say, 'That's it. You'll never be famous. You'll never be famous,'" Louis C.K. said during the interview. "'There's no way you asked Sean Penn a question and then you're gonna be huge.'"

Cut to a vintage clip of a young Bradley Cooper asking Sean Penn a thoughtful question about one of his characters. "Hey Mr. Penn, my name is Bradley Cooper," Cooper introduced himself while in the audience of 'Inside the Actor's Studio.' "I'm a second year actor," he said, before launching into his question. As Penn answered the question, Cooper sat forward, listening intently to every word the veteran actor said.

Of course, the video then shifts to a clip from 'American Hustle,' when Cooper (in character), walks through the door into bursts of applause and cheers, and he immediately goes to give Louis C.K.'s character a difficult time.

Best. Mashup. Ever. Watch the video above!