The first step is to recognise and acknowledge that it has happened. Then take a step back as you consider your response. It is really important to take time to consider everything rather then reacting from feelings of frustration and anger.
- I believe our agreed boundary regarding -------------------- has been broken.
- I feel -------------------------- about this
- We need to discuss this. (You may need to negotiate whether right now is the time to have a discussion or to set a more appropriate time)
- What behaviour is unreasonable (focus on behaviour not them as a person)
- What your feeling is about the behaviour (feeling not blaming response)
- Say what you want to do now or re-state the boundary.
It may be necessary then to re-state and/or renegotiate the boundary.
You may need to develop a 'broken record' technique – especially if they become defensive or start justifying their actions i.e. "Yes I hear what you are saying about why this happened but I still need you to keep to the agreed boundary"!
When making the above statement it is important to remember a few things because as with any new skill it needs to be developed, practised and refined.
Be prepared for them to try and put you off track, appeal to your emotions, argue, get angry etc. You may even need to have another person as a mediator or negotiator but if you do it is important that they trust the other party and the other party doesn't take sides.