Miss mimi: If it was so common and normal, why is it so frowned on today?
No it's not frowned on today. Maybe in the West but certainly is well and thriving in the oriental world.

Miss mimi : If it was natural too us, we would all be doing it.

Well sounds like fun but unfortunately it’s neither logical nor practical.
In order to propagate a species one male can have more offspring with many females than they can with a single female