During an appearance on the Tonight Show last night, the gorgeous 31-year-old model taught Fallon how to keep his body in sexy shape.
"Because you sit behind a desk a lot, right? Or if you're traveling," Kerr said. "When I'm on an airplane, there's a couple of little exercises you can do when you're sitting down."
"So you can tighten you ab muscles, you can clench and release, clench and release," Kerr explained while demonstrating the exercises. "And you're butt muscles, you can do that. You clench and release, and then you can alternate."
So that's how she stays so slim and fit!
Later on in the show, Fallon challenged Kerr to the classic drinking game of flip cup. "I've never played this game before," Kerr laughed. "But I've got to get into the American culture."
"This is a really fun game," Fallon encouraged.
Then they were off! Fallon and Kerr went down the line, drinking and flipping cup after cup. The game was neck and neck and came down to the very last cup. In the end, the star who won by only one second was...Fallon!
Watch the funny clips for yourself.