Set your boundary but do so in a calm but strong manner. There is no reason for it to be heated. W can overheat if she wants to but you stay cool calm and collected.

Best wishes

R 25 years
M 14 years
S11 & S13
Working on it alone since Oct 2014
M in trouble a lot earlier (~2 years)
Feb 2016. 1st R chat in a yr.
Next R chat Aug'17
Still together