We're seperated but we've been sleeping together

You have shared a life and children together and you still have loving feelings for him. So even though you no longer want him back, letting go is hard to do.

You were devastated when he moved in with this other woman when you were meant to be having a trial separation so the fact that he still fancies you is boosting your self esteem.

You could also be getting a kick out of getting back at her by having this secret sex with your ex. Starting again with someone new can feel kind of scary so you are settling for what you know.

None of these are good reasons and they are allowing him to take advantage of you. You have a lot going for you in your life so don't spoil it.

It makes you too vulnerable, stops you moving on and making new relationships and is thoroughly confusing for the children. It's time to say no and instead concentrate on your joint parenting role.