This is the process I usually reccomend yes...

You want to assert yourself, with dignity and maturity, while ensuring he acts in a way that respects you.

No one finds a doormat attractive... Once you start sticking up for yourself you have a better chance of impressing him.

Never mind what he "considers" OW to be... YOU press your own values into this that put children first...

OM "considers" it ok to threaten marraiges too... with children! That's pretty SICK!