Their "loyalty" causes them to lean forward, over invest and pine.
Plus, it's totally one-sided: The woman is committed to this non-relationship and he's not. Here's the truth: Dating more guys will make you much more attractive to men than loyalty.
This is why you are over-invested in the first place because you arrive before him and expect him to be on the same page as you.
The exact point of multiple dating is that you SPREAD your focus on many guys until one steps up.
And these women get even more desperate, they chase harder and he retracts further, and the cycle continues....
They treat these guys as their boyfriends when the guys are not treating them as their girlfriends.
You should go back to your life after, instead of obsessing about him which, again, is why you have this pining energy that turns men off.