The more the baby sucks more milk the mother's breast produce. So the top was low-key helping the bottom to feed their child. I do not recommend the father being the one sucking the breast though.
"Why don't you sell me and buy a rabbit instead?" "At least the rabbit will behave better than you!" "Go ahead, then, you'll be happy Cuz it'll be smarter than me too!"
The more the baby sucks more milk the mother's breast produce.
So the top was low-key helping the bottom to feed their child. I do not recommend the father being the one sucking the breast though.