Indeed, natural selection discriminates against well-behaved losers. - Olivia Judson

Evolution does not obey human notions of morality, nor is human morality a reflection of some natural law. The deadly sins would be different if they mirrored evolutionary no-no’s. Lust, for one, would be deemed a virtue; chastity would be deplored.

Boys, I’m afraid the way to a woman’s bed is often through her stomach.

If a proclivity for promiscuity is genetic, then yes, promiscuous behavior will become more common if loose females tend to have more children than their monogamous peers. That’s how natural selection works.