I have known two females who both would play out this fantasy from time to time and both quite enjoyed it. Well one of them started doing it out of necessity because she had this sex addiction that made her want to perform oral sex on men constantly. Every guy she knew (including me) she wanted to do five times a day each and would still try even when you didn’t want anymore. And I remember her saying that she started getting off on the whole thing of men paying her for it.