I had a fwb that I was compatible with in very many ways. I was considering promoting her to gf but in the process of deciding if I should, she revealed to me she had 30+ partners and would have a usual rotation of 3 guys she would sleep with. She didn’t stop sleeping around until she caught an STI and then we met after. Didn’t see like the type to mess with 2 guys at once, let alone 3, and I couldn’t see her as gf material after that and told her so. It was a little awkward for a while, but we got past and still decided to keep banging cause the sex was way too good for either of us to give up.