Women weren't second-class citizens in those days. They weren't citizens at all. They were property. Women did not have any rights or social contact apart from those bestowed upon them by their respective owners. Of course the owners of women often had one-way consensual sex with their property, but they also had two-or-more-way consensual sex with one another (as did the men who did not own any women). All men, one might think, had sex with one another and with their property. Houston, however, abstained.
Clearly a system of ownership and economics had been established by this moment in history, but society had not yet come up with ideas like "job", "career", or "profession". Houston invented those. He noticed how much pleasure other men got from reciprocally consensual sex. He gave up his abstinence -- but he charged a fee!
He put on quite the show of desire as he seduced man after man and used their money to buy their women from them. Eventually, after not much time at all, he built himself a harem. And so, the first prostitute was also the first pimp.