When someone says or does something really funny, then recreates the moment with a different crowd and pretends that this was the first time they did/said that funny thing. Usually used to get attention, or a bigger reaction.
Sarah: ohh I like your leather jacket Matt! I hope it doesn't get wrecked in the rain!
Matt: Thanks! It won't get wrecked, think about it, cows don't get wrecked in the rain, and leather is from cows...!
Sarah: haha!! you're so funny!
(a littlle while later)
(Matt is with other friends in his jacket)
MAtt: Do you think my jacket will get ruined? Since its raining and all?
Lauren: I hope not!
Matt: Well, i guess since leather is made from cows, and cows are waterproof, it will be fine.. !
Lauren: haha You're so funny Matt!
*Matt has just live in fived*
Person 1: Oh my god, Jakey is so funny! He just compared Adriana to Julie Andrews!!
Person 2: Wait, he totally just did that five minutes ago in the cafeteria! And it wasn't funny.
Person 1: He must have live in 5'ed it.