daddy rough play

Show him videos of kids accidentally falling, that should do the trick! Just kidding, but definitely make sure you sit him down and tell him the laundry list of possibilities and the consequences should he accidentally slip and lose control! Here's a link on the topic of dropping your baby, of which highly advises you to try everything in your power to prevent it from happening (purely because babies are incredibly fragile and a simple fall could cause irreparable damage): https://www.fatherly.com/what-to-do-if-you-drop-your-baby-on-the-head-1392332923.html