J.F.
L.,
I hope you'll take what I'm about to say in the spirit it is intended, and that is to help. I'm a step-parent and have been for a long time, so I know it's not always easy to navigate all of the different factors that go into blended families.
Anyway, to start---Your bf, this child's father, needs to step it up and take a much more active role as a dad.
You spend a lot of time talking about the mom, and from what you've written, there may be some issues. HOWEVER, your bf cannot change her. He can only control his own behavior.
It doesn't sound like your bf's health issues are so severe that he couldn't drive over to the home where his son is living and pick him up so they can spend some time together. It's been way too many weeks since they've been together. Definitely, this texting thing has to stop. He needs to pick up the phone and call his son and talk directly to HIM, not through the mom.
Your bf needs to make every effort AND then some to show this child he will not give up on him and that he loves him. Words aren't enough.
Of course the son is acting out, being surly, and trying to push dad away! He's desperate to know that his dad cares about him and loves him enough to make every effort to have a real father-son relationship with him. Your stepson isn't doing this on purpose. He's obviously confused, feeling alienated from his dad, and doesn't know how to make sense of all this and make it better. And why should he know? He's a kid!
It's up to all of you grown-ups to do that. Encourage your bf to make arrangements to spend more one on one time with his son on a regular basis. Time that is just for them. This boy needs his dad so much, especially at this point where he's soon to be a teenager.
Always make sure he feels welcome when he's with you----not like a guest at dad's house. Take time to really listen to him----even if it hurts your feelings. He needs to know he can talk to you and dad about what he's feeling.
Watch how you "talk" about your stepson. I know (okay, I really hope) that you'd never say "sarcastic spoiled brat" out loud, but if you *think* about him that way, those thoughts will influence your attitude toward him, and people, even kids can pick up on that. I know you're feeling frustrated, but I urge you to change your thinking from "sarcastic, spoiled brat" to hurt, confused, sad boy who desperately needs strong, stable adults in his life.
Is your bf paying his child support regularly? If your stepson needed some school clothes, why would dad respond in the way you wrote (text stating he'd help when he---dad---gets back to work)? Really? You didn't have enough set aside to buy at least a pair of jeans and a shirt? Or was this a way to mess with the ex for taking him back for more child support? I think I'd feel like a low priority if my dad couldn't even find a way to help provide a few pieces of school clothing. How were you taking care of your other family needs? If it's really true that one outfit was completely out of the budget until bf went back to work, then your bf should have sat down with his son (or at the very least called) and explained this.
Your bf and his ex need to learn how to talk to each other in a way that puts their son as the priority. Old grudges and lingering animosity have no place in this equation. Doesn't matter if they don't like each other or would rather avoid each other. For the sake of their son, they must learn to put him first and talk to each other civilly and with his best interests in mind.
You can help by encouraging your bf to do these things: talk directly to his son; spend one on one time with him; talk directly with the ex about issues related to their son; learn how to co-parent with her.
If they can begin to do this on their own, great. If not, don't waste any more time and find a great family therapist who can help all of you through this. It would be most helpful if his ex would participate in this, too, but if not, you and your bf should go with your stepson.
You guys have to get on the same page with respect to co-parenting this child, while he's still a child. You've got just a short time before the teenage years begin, and then, in just a few years, he'll be an adult. Help him grow to be the best young man he can be by being the parents he needs.
Wishing all of you the best.
J. F.