Or perhaps she should stay out of pool halls.
I agree that a man providing a woman with a beer should not be seen as putting her under an obligation to have sex with him.
A woman providing a man with sex, similarly should not be seen by her as putting him under any obligation to provide her with a ring at any point, or any other form of future commitment. She should see it as just an opportunity to have a pleasant time in his bed.
Nor should a woman engaging in sex with a man be seen as putting him under an obligation to provide her with beer. Equal rights, y'know.
Don't get out much, huh?