Please do correct me if I am wrong, and I likely am, but from what I always hear a 'slut' is not a woman fucking 20 women, but rather a woman fucking 20 men.

The kind of slurs these men use when they slut-shame women are often relative to men. She is a 'CUM-dumpster', she 'took in ten DICKS', she 'has been used by that guy'. Somehow, however much I do not doubt these men hate these women, I think their disgust has a lot to do with disgust for other men, too.

P. S. Another thing which just came to my kind is that racist men see a woman who has slept with a man from their hated group as 'damaged goods'. Again, interesting how the focus is not the woman's sexual desire, but the man and his sperm.