Why would anyone want to settle as being the other woman/man?

I caught my ex cheating with his ex. All throughout our relationship, his ex was still in the picture trying to butt in. My ex reassured me that I had nothing to worry about, while he was busy hooking up with her behind my back all three years of our relationship.

I stalked his ex’s account and saw that she kept on preaching about being a boss babe, about maintaining your self worth as a woman, about self love and not settling for less. But I remember she texted my ex begging him to take her back even if only as a side chick.

She’s in her mid 20s and seems successful so I don’t understand why someone like her would be okay with being the side chick? My ex wasn’t really a prize either in all honesty. Yes he was extremely fit and attractive but he was also emotionally unavailable and very manipulative. So why?

Why would anyone want to settle as being the other woman/man?
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