Instead, because humans developed a taste for face to face “bonding,” the woman's breast mutated to imitate the buttocks which swell, attracting male attentions, in all female primates when in estrus.
Natural Selection made the female breast a sexual enticement in order to add to the woman's physical attractiveness because lasting pair bonding in a species where young are long developing is vital.
So according to Anthropology 101, female breasts are both functional (though very large mammaries can obstruct infant breathing) and sexual by nature...and Time is obviously exploiting the latter.
“the woman’s breast mutated to imitate the buttocks which swell, attracting male attentions,”
That may explain why so many women think they deserve to have their asses kissed.