I don't think that is a responsible AA way to handle things at all! Walking out on bills without talking with you and working out an agreement that covers both of your needs. I will say that isn't love as I understand love. I would be (and have been when my X decided a year and 1/2 ago that he was walking away) very outraged, hurt....felt like hanging/shooting/drowning him (as an X-professor used to jokingly say. And I have the sick feeling that you may not get child support?
I wouldn't want him to sail in and out of the house and be around me either.
I am so sorry that you are going through this.
Please do whatever you need to to protect yourself in this situation.
You might take him to small claims for his share of the bills??