"Expressing your boundaries passively, such as withdrawal, triangulation, pouting & passive aggressive behavior, are extremely destructive to a relationship. Passive ways of showing people that they do not have control over you never lead to intimacy. They never educate the other on who you are, they only estrange.
Don’t use passive resistance. Don’t pout or withdraw. Say things like, "I do not feel comfortable with that. I do not want to. I won’t."
excerpt from Boundaries by Dr. Henry Cloud & Dr. John Townsend
I'm not sure if I'd like this book, because it's Christian and peppered with references to god and the bible, but I do like this part for sure. I think it is really important to remember this!