RTFM
The epithelial lining of the anal canal is fragile and not designed for friction.The vagina, OTOH, is lined with durable stratified squamous epithelium.
An objective, physical example of Natural Law.
The vagina is designed to push out an eight pound baby.
No point in telling this to a person who resents being told that his actions should in anyway be restricted by the design of his body.
New pickup line: “Hey, baby, want to test the durability of your stratified squamous epithelium?”
The oral cavity is also lined with durable stratified squamous epithelium. So by that measure all males who engage with other males in oral copulation are within keeping with Natural Law?
Come on. Do better than that. I know you can.
Bill Nye is a mechanical engineer. You’d think he’d know that.