Steer likes to jump

We have had issues in the past where when we are at a show, our steers like to try and jump on others in the ring.  It's not safe and with younger showmen it makes it even worse.  My youngest is starting to show this year.  His steer we have at home is as gentle as can be except he likes to ride the others in the barn when ever he has the chance.  What can I do to break him of that.

Everytime he starts (when he is being led) give him a jerk on the lead and a good thump on the nose with the showstick, if you stay consistent on it he will get to where you just need to put the showstick in front of his nose and he should change his mind.

Great Suggestion VC!  Experience talking right there...