"Somehow I don't think this is a very appealing society to girl lovers, to see your special little girlfriend giving or getting oral with anyone who asks. Maybe for some it would be appealing.

Nanook of the North nonwithstanding............

Very recently the society WE were born into had issues where for many, if not most, it was similarly undesirable if your GF ( L or otherwise ) had a lover previous to you. And a generation before that, had spooned or been unchaperoned before you came along.

Again, it was argued that expecting this of her, but not of him was because females were just "special" that way ( though always argued as such by men. )

Heck, all of this smacks of the false appeal to specialness, "You can't be best friends with him if you want to be best friends with me." This appeal is usually made to the vulnerable. And we support them when we disabuse them of the notion that specialness lies in exclusivity and in withholding natural affection so as to not "devalue" it.

As for the bottom dropping out of prostitution........

It largely has compared to what organized prostitution was in the past. It is no longer the largely tolerated cultural institution in which the upper echelons of society sent their sons to be "educated" and where the mayor and a councilman might accidentally meet in the waiting room of a Maison Close.

The bottom fell out when the madonna/whore dichotomy was largely rejected and when premarital sex and recreational sex became more acceptable.

Prudes can argue that women choosing either have made sex less special, themselves less special and have been bamboozled by the patriarchy to conflate their desires with the wicked, wicked lust of those unspecial males. But the more the bottom falls out of the market, the better off women are.

( And one could also argue that by linking the promise of long-term sexual availability to cohabitation and marriage, and by allowing the customer to try the "wares" before settling, the woman whose choice would've rendered her a "prostitute" in a previous culture has improved her status. )

Dante