Also inside me though is the momma bear May who will take just about any level of $hit someone can throw at me to protect my children, but as soon as they're hurt she's ready to take zero prisoners and give zero f**ks about H in the process. Hurt me? I can handle it. Hurt my kids? Now we're on. I have absolutely no worries about enforcing my boundary of if he walks, I want nothing to do with him.
What do you consider “hurting your children”? Although your children might not know what’s going on yet, they are already deeply effected by your H’s decisions (or lack thereof). Your H has been in this A for 2 to 3 years, actively choosing to behave in a way that is detrimental to your M, and thus your children’s well-being.
I just want to point out that if your definition of H hurting the kids is “H walks out, the kids will know, so it’s over”, maybe it’s worthwhile to think about it more. Why will it take him physically leaving the house for you to give zero f**cks about him? He has chosen to leave you and your children over and over again by being in an A.
I know you said to be gentle, I’m sorry if I sounded too harsh. You didn’t break up the family, he did. Choosing to end the M is only ending the contract. The M is already lost. You shouldn’t feel like you need to bear the weight for that.