Tom Cruise Talks J.Lo Butt Slap (VIDEO)

Tom Cruise visited 'The Late Show' Thursday night where he chatted with Jay Leno about Jennifer Lopez slapping him on the butt during his performance (as 'Tropic Thunder' character Les Grossman) with her at the MTV Movie Awards.

"Whose idea was it, having you slap her in the ass, was it your idea?" Leno asked.

"That was my idea -- it's Les, it's Les!" said Cruise.

"Now was there a lot of practice in that?" said Leno. "Because you're obviously turning red, there's more to the story."

"No, there's no more, there's no more to the story. It's a character!" Cruise said.

He also said he could barely feel the slap because of his cotume's padding and that wife Katie Holmes "was impressed" with his performance. Cruise is promoting his new movie 'Knight and Day,' out July 2.