Why should it be the responsibility of the woman to make it clear that she does owe the man in this scenario sex for buying her dinner? The vast majority of parents automatically make it clear to their sons that a woman never OWES a man sex. Why would you ever wish to encourage any man to think any such obligation exists? The very idea of that turns any dinner date into implicit sexual consent- does any possible good come of perpetuating a damaging idea like that?

Parents should be raising their sons, and young mean should be reminding each other. that sex is NEVER. under any circumstances, owed to them.