Where exactly does he say that he stood up for himself ey? WHERE?
Let's face it - he has not got much left to lose in this situation - so she got rattled - tough shit although obviously caused Nick some distress.
What on earth does she expect him to do - be a muppet and say nothing, accept that this is all fine and that he is perfectly happy with the arrangements
Other people are entitled to their opinion and though she may angrily disagree and deny any of what was suggested or discussed he has a right to feel the way he does.
Attempting to have reasonable conversations may be a little ambitious at this stage though