[ToxicFemininity] It's biologically impossible for women to be loyal in the present world

Sex among life on Earth exists because having multiple genetically diverse offspring increases the probability of at least one of those offspring surviving in an ever changing environment. Right now, the entire planet is changing in way never seen in human history. Population explosions, climate change, migrations, extinctions, and it's all apparent for everyone tapped into the modern communication structure based around social media. The Australian fires are as "real" to American women as if they were in California. This exposure to a hostile environment triggers the female hind-brain to want to take action to increase the probability of her offspring's survival in an uncertain future. Being loyal to a single man handicaps the chances of having successful offspring because there's no environment on Earth stable enough to facilitate the benefits offsetting this desire for diverse offspring with the benefits of a stable male/female relationship.

tl;dr
The is no "settling down" anymore. Women's subconscious is permanently in promiscuous mode.