I'm upset with my friend for pretending to cut
What are you going to do about your friend?
I want to confront them about what they did.
I think you are right in talking to your friend about what they did. It's bad to act like you want to self-harm when you really don't. There are many people out there that really need help and pretending to do something like that is wrong.
I'm going to let them know that they shouldn't be so rude and that I don't appreciate them lying to me.
That's good to hear. It sounds like you are on the right track.