Is there a biological reason behind this behavior?, or is it just another consequence of society's over-sexualization and the widespread availability of porn? Was this that common in the pre-internet/tv era?
I know that many animals "do this" (in some form or another), but that respond mainly to their need/instinct of procreation, and whatever the case, they never go as far as cramming their heads in cunny with such high commitment and devotion.
But man does, and the vast majority of men enjoy it. That's an undeniable fact.