Hi Gab,
I am so sorry for you. Big hug to you. Is it possible to tell him not to act in a way that will confuse the kids? Have you discussed how you will tell the kids. The ideal situation is if you can have a friendly divorce for the sake of the kids. All I can recommend is discussing it with him about how to handle this for the kids. I am again sorry for you and send a dose of strength your way.
Big hugg...Sesquix