While on a motorcycle ride, he taps the young boy in front of him on the helmet and hands over complete control.
Unfortunately, we have no context for this video. The YouTube description just says, "6-Year-Old Boy Riding Father's Harley On An Open Road!" So it's difficult to say where this is happening or when. Regardless, it's almost certainly against the law to let a child ride a motorcycle on public roads.
To their credit, both of them handle things quite well. On the adult's side, they don't appear to pass any traffic during the video, and he waits for a long, straight piece of road for the kid to take over. The little boy is pretty cool too. He nonchalantly grabs the handlebars after two prompts from the man and gives the throttle a good twist. He doesn't seem afraid by any of this.