What would you do??! best friend/?

I don't think anything she did is "disgusting" or "gross". It's not like she groped you, don't make it such a big deal! I think you're over yzing the situation. Don't give it another thought unless she does something else that makes you uncomfortable. If that should happen, maybe you could sit her down and explain to her that you love her as a friend, but just don't see her as anything more. If you say it in a respectful manner, it shouldn't upset her.