Ex girlfriend of 3 years turned into promiscuous tramp?

She dumped me in August after cheating/Gigs etc... I've been utilizing NC for the pass 2 1/2 months and she's been sleeping with basically any dude that's willing to give her attention. She left me to pursue something with another guy (not sure how that's working out), but she is also sleeping around a lot (her best friend told me, I didn't ask). Is this common behavior for girls coming out of a LTR?

I don't want her back nor do I have any romantic feelings left (I think), but I feel humiliated that someone I've loved is acting like this. I know its should be none of my business but I'm just curious to know why!
Ex girlfriend of 3 years turned into promiscuous tramp?
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