A PRIEST AND A RABBI WALK INTO A BAR ... Timberlake (Photo: Getty Images)

Justin Timberlake is bringing douchey back, one cocky awards show appearance at a time. During the Rock and Roll Hall of Fame speech rehearsals for his later introduction of inductee Madonna, the pop star spent much of his time lazily rolling his eyes and head, and even breaking into random song as he half-assed his way through his recitation, says a witness.

Timberlake's attempts at humor flopped, and breaking into a falsetto sing-songy funnyvoice after botching a scripted line didn't help. Then there was the attempt at ad-libbing a joke about Madonna kissing Britney Spears ("She's someone that may or may not have famously kissed someone I did. While I watched. And I'm talking, of course, about Sean Penn."). "He was a little red in the face and looked uncomfortable," said our rehearsal witness. "His first few stabs at humor were shot down by the producers, who were trying to keep him closer to the script. He was receptive to feedback but you could tell he wanted to put his twist on it." He's an actor now, after all.

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