Males who:
1) are able to achieve and maintain an erection
2) will not give oxygen to whores who are either sickeningly overweight or otherwise intolerably homely
3) recognize that the paying customer has no responsibility whatsoever to make any attempt at all to sexually satisfy the whore, but instead that it's the whore's job to make him happy, period.
4) resist the urge to provide a psychological support system to someone they are simultaneously paying money to for the short-term use of her ass, etc.