I have always carried a sorting stick when moving the cows. If a bull calf was doing this with me, I would whack him on the nose with a sorting stick when he showed this behavior. My cows and bulls respect a sorting stick. I don't beat them with one, but they do know when they see me with a sorting stick it is time to be moved, and they start looking for an open gate or the trailer. I can walk right up to my cows if I don't have the sorting stick in my hand. I have found the bull calves usually need the whack on the nose lesson in order to behave around humans as they grow older. Because of lessons learned as young animals, I can walk into the bull corral and load them into a trailer . . . as long as I have a sorting stick in my hand.
Don't put up with this behavior from your calf. He is testing you. He wants to know if you are a playtoy. He's old enough for a lesson.