Saying NO sometimes might be very had to say but sometimes it worth saying. Learning how to say NO when it is needed is a secret to living a happier life. Forget who the person is, what matter is your happiness.
If you think ,it will hurt the person them wont it hurt you if you would say YES?. If your answer is Yes then say NO when demanded,your happiness and joy is the ultimate because your word (NO) is your bond.
I hope you won't say NO if i ask you to be my friends?..lol.