I cringe at words like "blame," "fun parent," "perfect dad," "bad guy," etc. It's not us vs. them. Or at least it doesn't have to be. When I separated from my husband, I explained to my children that their father was sick. That he wasn't "bad," he just had an illness that caused him to make poor decisions sometimes. And that until he took the initiative to get himself better, I would be protecting them and myself from the outcome of his poor decisions. I let them know that we both love them, we just can't stay together as husband and wife. That the problems between us are adult problems. Also, something emphasized over and over by our counselor, was to stress to them that NONE OF THIS was their fault. Seems obvious to us adults, but children internalize and blame themselves for everything. It must be stressed continually that they are not to blame, and there is nothing they can do or could have done that would change things. I cannot stress enough how important this is!
L