MMA with your child

What if you were playing MMA with your kid. You get a take down. Then you begin a ground and pound attack on them. The kid decides his only chance is to give up his back. Seeing this you go for a rear naked choke hold. Is it okay to choke the kid out if they refuse submit because he knows you are his dad and you will not choke him out for real? If you think you can choke them out, how old must the kid be?