Hey
My girlfriend Carolyn wants to be my girlfriend again. I told her that I would think about it and
Tell her later. Then, her friend Cerny wants me to say NO! What should I do because if I say yes Carolyn will be happy. If I say no Cerny will bw happy! Which way should I go?

Which ever way that makes YOU happy

You can't worry about what other people want. You can't please everyone all the time, and even if one of them gets a lil' bent out of shape, at least you'll the comfort knowing that you made the decision that you wanted to.