I'm going to say a girl I slept with has a sour cream dip smelling vagina
That seems rude. Why would you tell her that?
I heard she slept with another guy and I don't like sharing
It is wrong to spread rumors about someone because you are upset. What if she did the same thing and said something bad about your private parts? You wouldn't like that as well, would you?
I don't care. It has nothing to do with me. Right now she is being a whore.
This is why rumors are dangerous. It gives people false assumptions. Why don't you talk to her first to figure out whether things are true? You might be angry over something that never happened, right?