"DH, I'm done dealing with your son and ex-wife. You have two choices: Start putting me first, and we can talk about how to do that, or I leave. I want your final answer by Monday."

Then let him stew. In the meantime, start looking for an apartment and marriage counselor. If he chooses to out you first to save your marriage, then tell him you want to see a marriage counselor pronto. If he hems and haws, tells you it isn't fair/you just hate his son/he is trying but this is the best he can do, or tells you that he's done, move out.

This assumes you have the resources to leave. If you truly don't, then start making an exit plan. Save money, get a second job, find a roommate or family member you can live with until you are back on your feet. Whatever you need to do, do it.

No matter the outcome of this decision, you do need to disengage from your SS and block communication with BM. You have no reason to communicate with her, so block her from your phone. Don't ride along for drop offs and pick ups. If your DH starts talking about her, tell him you don't want to hear anything about her, then walk away.

Disengaging from SS means letting your DH handle EVERYTHING. SS doesn't do his chores? Tell DH you want them done and you don't care if he or SS does it. Needs breakfast before going to school, or a lunch packed? DH. His laundry needs done? DH. Needs reminded to shower or do homework? DH. Be polite to SS when he is around you, but if he asks you for something, direct him to Dad. It's his job to parent, whether he's tired or not. Make him parent or make him be the one to allow SS to get away with murder. Your responsibility to your SS is the same as in any other in your home - make sure they don't get hurt or die, and make sure he eats at least one meal (which, if you're cooking, should be exactly what everyone else eats; nothing extra or different).

Your DH won't like it, but so what? You're an equal adult in your household, and you shouldn't be subjected to disrespectful and rude behavior so that DH can continue an unhealthy relationship with his son and ex. If he wants that kind of relationship, he can have it alone.

Nifty thing called divorce court. Now way in hell i would live like that.

"...and now as my son gets older I have rules in my household and my stepson does not like this. He has zero rules at his moms but here he's asked to clean his room and he's told no as well as sent to his room if he acts up".

Well, the first mistake was allowing and/or tolerating slacked establishment of rules and expectation right from the get-go. Yeah, no going back and doing things differently now, but it does explain why BM and her "sweet" child do not want any part of your rules and expectations now. Dad should have always parented and held up expectations of behavior and household participation. It would not matter how coddled and spoilt he is at BM's because SS would have spent the other 50% of his young life being taught to behave in your home. But meh, going back and redoing now.

"The other day my stepson told my son he hated him and to get out of his face".

If nothing else, this should have knocked into your DH's head that he must stand up and begin to parent. Both these children are his children. Allowing his oldest son to be a brat and Dad fearing to parent the child, discipline and have rules and expectations with consequences is going to get Dad a younger son who resents his father for Dad letting the older child be mean to the younger, for allowing the older to slack while the younger must be held up to the rules and expectations.

And the communication? Lady, block BM from having any contact with you. The phones, the emails, at exchanges ... whenever and however this woman is reaching you just stop. And your DH? He is doing this kid no favors by fearing to parent or lacking to parent out of some guilt over the divorce. In fact he is failing both his sons. One will grow up believing the world is to cater to him and he is entitled to be treated special, the other younger child will grow up resenting his father, having no respect for his brother or father.

I will assume the oldest child is home now for winter break and therefore under your feet more time than usual (no school), and of course summers 24/7 two weeks a month. I suggest you explain to your DH that you will no longer babysit his older son during DH's absence from the home. The kid can stay with BM and be picked up when Dad is off , or go to daycare or hire a babysitter that will have the boy in their home. If the child won't listen to and behave for you and his parents won't parent their own kid, why should you be expected to?