Flexible or Flimsy

There is a presupposition in NLP that states that the meaning of your communication is the response that it gets. This points towards behavioural flexibility, but what happens if that person is being aggressive, or dismissive, or abrasive, or imposing on you?

How far do you take this behavioural flexibility? How do you know where the line is drawn, or do you keep changing? It’s a good idea to be sure of what it is that you want, your needs, requirements, demands, and what your limitations are, then you know how flexible you can be within that.