Oh no, this is my worst fear. I would be furious but after thinking about it, I would probably pretend like I didn't know it happened. Just tell the rest of your friends when you want to and if THEY act surprised (as if they didn't know) then run with it but if they act all "old news" about it, I would have a bit of a pointed comment ready so its obvious you are annoyed. I like the "Oh that was nice of such and such to share my news" like mum2romone said.