They'll get over it though Hun, you have to say your piece and if they chose to take it overly sensitively then that's their own fault, you have a valid point to just say that you have been upset that they have discussed something that was private to YOU, about YOUR body, and what you specifically asked them not to tell anyone. They need to understand boundaries and even if they do feel like you are the bad guys and they have done nothing wrong, they will get the point and won't do anything like it again.