Explain why it's a wise double standard.
But a man can never be sure when his woman becomes pregnant, that the baby is his.
And so a wise man knows that a woman who refuses to have sex with anyone until marriage, is a woman more likely to be faithful after marriage--for she strictly follows the rules.
Were it otherwise, a woman who finds excuses to have sex prior to marriage, will find it easier to find excuses to have sex outside of her marriage.
Such a woman shows she is weak and more likely to make excuses to herself to break rules when temptation comes along.
I would never marry a woman who had sex with me before I married her.
But I would have sex with her.