I have a "friend" and she keeps saying its gross for me to be bi how do i tell her i dont wanna be her friend?

i told ppl that im bi wwwaaaaayyyy to early and now there all "ewww" and im trying to tell ppl that it was all a joke so they'll stop making fun of me but jillian (the so called friend) keeps bringing it up i just want her to stop it but i dont think thats gonna happen if i keep being friends with her. (in other words) shes a cold heartless ***** and i need help getting rid of her