I'm mad at my girlfriend for popping my pimples
Why are you mad at your girlfriend for that?
She should have asked me first, before doing that.
You have the right to be mad because popping pimples pre-maturely will leave scarring on the face which is not good. She didn't ask you first so that is not respecting your boundaries.
She knows my expectations in this situation so she should know to not do that.
I agree with you, it's not healthy for her to do that and in the future I hope she asks first.