Just wanna be careful with those girls, Biff, that’s all. Don’t make any promises. No promises of any kind. Because a girl, y’know, they always believe what you tell ’em, and you’re very young, Biff, you’re too young to be talking seriously to girls.
– Arthur Miller
Death of a Salesman, Act 1. Willy shows himself to be a poor role model to his sons, with this kind of terrible advice he offers them about how to treat women. He is essentially telling Biff that women are not to be trusted and he shouldn’t make any promises to them. Foreshadowed here are now shabbily the Loman men treat women. Linda observes that her teenage Biff is "too rough with the girls," Happy grows up to be a womanizer who has sex with the fiances of his managers, and Willy is unfaithful to Linda.