Thoughts on the so called dual mating strategy, mate switching hypothesis or ovulatory shift hypothesis? I guess this is what TRP calls hypergamy.

​

"One study found that women are most likely to evade their partner’s mate-guarding efforts precisely around their most fertile phase – an effect most pronounced among women partnered with men low in attractiveness. These women find themselves more interested in attending social events, perhaps because they might interact with alternative mates. And they report engaging in greater flirtation with men other than their regular partner. These findings point to the possibility that women monitor their own mate value, and when it increases, alternative mates can seem more attractive. This, in turn, requires monitoring alternative possible mates. According to the mate-switching hypothesis, scanning for alternative mates remains activated even among those in happy relationships."

​

"Recognising that humans have evolved a psychology dedicated to mate-switching undoubtedly will be disturbing to many. It might be disconcerting to a man to realise that his wife is carrying a mate-insurance policy, harbours sexual fantasies about her co-worker, or has ‘just a friend’ who is his rival. It might be depressing to realise that you are more replaceable than you knew. It could be disturbing when it dawns on you that your partner’s unhappiness might not be transient and instead portends a hidden plan for exiting the relationship."

​

https://aeon.co/essays/does-the-mate-switching-hypothesis-explain-female-infidelity