I hear you, but you have a DH problem too. Manipulative, controlling BM and weak, enabling DH = step hell. Your DH is the one who needs to put his foot down with her. He needs to be dealing with her. She is his -ex; she is not yours.

However, this is one of those not so lovely situations that SMs find themselves in all the time. If DH refuses to pay BM's light bill, for example, rather than she figuring out a way to do with less, she'll more than likely have the kids do without and claim DH is a deadbeat dad and so on. Years down the road, BM and kids will use this is an example of how horrible bio-dad was--refusing to pay their light bill, even tho. BM could have just as easily done so. (By the way, what does she have going on in her home? A growing co-op?)

Also, as a SM, with the court system, you don't exist. It is all about BM and the kids and DH (somewhat). This is why as hard as it is, when you become a SM, you can have SKs over and interact with them and your husband, but otherwise, you have to stay out of DH and BM's dirty laundry as much as possible. This is a matter that DH and BM need to handle. And, I know it is hard, because a lot of DHs will practically beg for their wife's help sometimes. You can give advice to DH, but that is pretty much it.

And, yes, I know that BM is making poor or self-centered decisions that affect you and your DH and your own household and certainly your own pocket-book. Believe me, I know how that goes. But, if you get too involved you will not accomplish anything for yourself other than heartbreak and resentment. All you can even remotely influence in this situation is your DH. Your DH is the one who has to see the situation for what it really is and act accordingly.

Yes, unfortunately he is stuck with that light bill. Hopefully, he learned some sort of lesson now and it won't happen again. I almost think what DHs need to learn is almost the same as what SMs need to learn--you are damned if you do and damned if you don't. Fool me once, shame on you. Fool me twice, shame on me.

He pays the bill and then tells the electric company and then gives her 24 hrs to get the bill in her name. Sadly this is the way it goes. She COULD go to the State and ask for assistance. They will work with her. But this means she will have to get the bill in her name.
How long has this bill not been paid to run up that bill and not get the power cut off?
This should be a learning moment for DH and his kids. Bills get paid because that is how the world works. You do not sign up for anything you cannot afford.

Once the bill is paid he walks away from her financial problems. She said she cannot get the bill in her name yet she continues to use the power source. If the kids do not have access to a heating and lighting source then they come and live with you. Done. No histrionics. No drama.

I know you chose not to have children however marrying a man knowing he has children means you are always one breath away from being a 24/7 stepmother.

Your DH is part of the problem if he continues to do things like this for her after she stiffed him on that electric bill. Hopefully he will not do her any more favors that have the potential to cost him money.

It really doesn't matter what she thinks of you both, or what she tells other people. You can't control that. The only thing he can control is whether or not he agrees to do her these favors (allowing her to rip him off). If he says no, she will find another way.

I agree with all the above.... your DH is the problem, jumping when his ex demands.

He should simply tell her, her electricity problem is not his, they are divorced.... and then ignore her.
If the kids blame him for it, he can simply tell them the truth, BM does not pay her bills and she gets CS to cover costs, she spends it on junk and that's not how life works. You first pay your obligations then you party.... he can show them everything as well...

but instead he hides behind "it's for the children"