If you want to fuck your kids up for life, let them play in puddles. Lace up their yellow rubber boots, toss on their yellow raincoat, flop on their yellow rain hat, and send this little moving traffic warning out into the world. Tell them, you can splash in puddles if you do it quickly, but do not play in the puddle.
Treat it like smoking. Show them photos of saggy butts. Ask someone with a saggy butt to rub their saggy butt on your child. Gross them out so they understand. Snap their sense of reality. Teach them that when you have a saggy butt, sitting becomes an expression of sadness. Talk to your kids and help them maintain poster-worthy posteriors.