How old is your SS? Your DH should have discussed it with you before just assuming you would watch SS since you work from home. It drives me nuts to hear that DH's just assume skids can be at home when SM's work from home, because you are still WORKING...since when does anyone want to babysit while they're working?? Anyway, it sounds like you are at least 1 foot out the door, on the verge of leaving. Why not put all your cards on the table and tell your DH that you are struggling with the SM role and something needs to change. I don't know if SS not taking the bus is enough, but maybe there are other changes that can be made. If not, and he is unwilling to help, can't help, or just doesn't care, maybe you are not cut out to be a SM, and there is certainly no shame in that...

Yes, how old is SS? Why does BM not pay for anything? Is SS with you full-time? Has DH tried to get Child Support from BM? YOU should not be on the hook to support SS at all - so separate your money and tell DH all of that is on him, if that's possible.

Anyway - welcome.

It's ultimatum time.  Tell your DH he must find afterschool care for SS IMMEDIATELY.  No ifs, ands or buts.

Because he's still going to have to have care when you leave his selfish ass.

My guess is you might not mind the lop-sided financial arrangement so much if you didn't have to parent SS all day, every day. So work on changing that first because that will get you immediate relief.

Consider other options for SS's afterschool care (like whatever the kid was doing before this arrangement was cooked up), afterschool programs or clubs, lessons, a nanny or sitter, whatever you can come up with. If the kid is old enough, he can volunteer or get a job. Put them all on paper.

Then sit your husband down and calmly tell him to pick one. Then tell him to implement the change with SS as soon as possible so SS can get into the swing of it at the beginning of the school year -- as in now. Don't ask your husband to change the situation -- just tell him to pick an option as if the decision has already been made. He should be familiar with that approach

He will probably ask you why. Don't bad mouth SS, just tell him the situation isn't working for you. If he gives you any lip, tell him you don't mean offense to SS, but "it's just not working for me." No matter what he throws at you, just keep saying it. You can garnish it with, "the midday interruption throws off my workday," or "I can't concentrate on work when I feel I should be tending to him," or even, "it's just not an arrangement I'm comfortable with yet," as if you someday will be comfortable with it, but always come back to it not working FOR YOU.

If he tries to say no or it becomes a fight, then you need to tell him, "This is not negotiable." If it becomes a bigger fight, you'll have to ramp up and tell him you're absolutely miserable with the arrangement and it is a hill you'll die on, but try not to bad mouth his kid. As much as you can, stay calm, don't defend yourself (you need not), don't get angry, don't swear...just keep plugging away at the message that the arrangement will change.

Don't let him push you around. Be firm. If this doesn't work, come back and we'll get you through the next step.

This is "ultimatum light" -- not too harsh to start, but the tension can be ramped up as needed.

You've had it pretty rough physically with medical issues. Extremely stressful. It's probably time to think about you and mentally doing for yourself rather than worrying about skids.

Where is the other stepchild (you mention two in your profile)? Are you expected to tend to both skids?

It's ok, to just inform your Dh that you're busy and not up to worrying about SS after school. He can make other arrangements. Without knowing the age of the SS, I can't give suggestions on possible other means... but bottom line, this isn't your child and you are not responsible for him. And yes, if BM is not helping out with the support of her son, by all means have Dad file for child support. It's the child's legal right to be supported by both parents. 

He makes 4 times what you make and he expects you to watch his son after school in violation of your work contract? What the hell? Cheap and doesn’t care about your job. Very nice.  He sounds like a gem. 

Good work at home jobs can be hard to come by, depends on your field, contacts, etc.

You are voluntarily putting yourself in a potentially precarious position.  Your present employer could let you go, and say, with all honestly, that you violated the [IMO reasonable] terms of your employment.  I would hope you would get a warning first, but that does not always happen.  

In short, you MUST put an end to this situation ASAP.   You have been married three years, and have no mutual children.  The bad news is that you would get no or minimal financial settlement in most states. The good news is, as you work at home, you have flebility to move (and he knows that!).   Tell him he has one week to resolve issue with what to do with his son, or you are moving out.  

My advice is to let him know this isn’t working for you. You raised your children and will not be the nanny to another. He needs to put his kid in after school care while you’re working at home or be there when he gets home. Meanwhile, you need to start a nest egg. Start putting money on the side and saving up for a place of your own. Start slowly separating your accounts. He will not take well to you saying you don’t want to mother his child so expect more rifts to come. Use those as determining factors on if you should move out and just “date” your husband until the kid ages out or just cut ties and walk away.