Clint's son was forbidden from mounting the bulls during filming of new movie The Longest Ride, in which he plays a wild rider, and so he sneaked off after the project wrapped and hopped on a mad beast just so he knew what it really felt like to be bucked.

He recently told WENN, "I was a big fan of the sport prior to the film. I knew some of the stars. I had gone to rodeo as a kid; I'd been to the Salinas rodeo.

"I took the role very seriously. I was hanging with the guys and watching them buck bulls and drinking beers with them. They never let me on a bull but I went behind (studio) Fox's back and they weren't too happy about it! I went and bucked a bull after filming. I didn't want to go around and talk that I knew what bull riding was about without really bucking a bull. I lasted about two and a half seconds!"

Now footage of his wild ride is to be shown on TV chat show The Tonight Show Starring Jimmy Fallon when Eastwood is a guest on Wednesday.

He says, "We have the video and we're putting it on Jimmy Fallon... It's gonna be the first time it's ever seen."