Seriously, he can be taught to do more and help more and you do not have any interference from the bio parents. Maybe read on here about BM and BD interference and that might lessen your resentment a little bit. And the child can be taugh YOUR way 100%. And if anyone gets in your way, well there will be no one getting in your way.

Get with other mothers, dont become isolated. That way you have a strong support system. Thats a super huge biggie. Enlist the grandparents and family members. Dont try to do it all. Many times we try to do all and be all and end up resentful.

Time for YOU to be selfish.  If SS moved in with you did CS go down?  DH needs to do the heavy lifting for SS and not dump it in you.  How much does DH lighten your load?  I'm bet not much or you wouldn't be here.   You have a man problem.  If you want to feel better , make the parents stop taking you for granted.  It is THEIR kid after all.  

They really just think you are supposed to be the parent huh? What a convenient situation! 

2 things: As CLove mentioned, sometimes not having the Bio parents around works better. You don't have to watch them coddling skids, you actually have a say. My DH works nights and I prefer the dynamic when DH isn't around. But, at least we have week on/week off custody and skids are 12 and 15 so in their rooms mostly, not like a FT 8yr old. Skids don't attention-seek as much when it's just me and it's just less stressful. They have chores and we taught them to clean up after themselves at a young age (I'm not a maid and nothing will fuel resentment faster than a SM who is expected to clean up after a skid all by herself), and they are not allowed to be disrespectful brats, which DH enforces even though he's gone a lot. 

That being said, you ABSOLUTELY need time to yourself in this deal, and DH better figure out a way for you to get it. Babysitter, days with his parents, who cares. You can't be expected to be with a kid that isn't yours FT. It's not fair and it's not realistic. You already have resentment- you need to speak up NOW, or you will just continue to be miserable.He is the parent, he nees to figure out a solution that works for both of you. 

I watch my two SDs, 7 and 9, on DH's days (mercifully he and BM are 50/50, so it's not full time).  It's the deal we struck for me being a SAHM - my DH doesn't make enough on his own to pay for childcare.  Since they're in school and DH works 7-4, it's not a huge deal.  I have to get them up and out the door, but he's home when they get home from school or shortly afterwards.  They're old enough to get themselves ready for school and make their own lunches, and they can entertain themselves.  If DH isn't going to be home for some reason and I can't watch them, I can usually arrange a playdate with one of their friends and then reciprocate another time.  I don't have resentment (most of the time) because it's really not a terrible imposition on me and I benefit by being able to stay home with my DD.

Since BM in your case has essentially bailed, is she paying child support that would enable you to use a before/after school program if that would help?  Or, since your H works a lot, is he making enough that he can provide you with help, whether with housework or childcare?  Is your SS fairly self sufficient?  If not, get on your husband about that.  His child is old enough to do a lot on his own, and it's up to him to get him to that point if he's not there already.  

Were you consulted before this major, life altering decision for SS to move in with you was made?  If not, I would be resentful too, and I wouldn't feel bad about being selfish.  You didn't sign up to have your SS full time with neither of his parents around to do the heavy lifting.  Is it necessary for your H to work as much as he does?  Could he work from home for part of the time?  Could he be more efficient and work fewer hours while accomplishing the same amount of work, or is he an hourly worker?  I'd have a talk with him about the need for HIM to step up and take a much more hands on approach with HIS child.

It is about the huge disparity you suffer from in your marriage. Time for daddy to step up and parent his children.  I get that he works.  So do  you, and your work occurs where you live and your customers are all 4 of the people you live with, or more accurately.... live with you.

Do not be appologetic on making your requirements firmly known with SS and DH.  Your two are toddlers. They are the ones whose turn it is to have your undivided mom attention.

And please tell me that DH has nailed BM's child abandoning ass to the CS wall and the courts are enforcing that she pays.

As for SS8 and his two younger sibs. I have nearly exactly the same age difference with my two younger brothers. I am both 6 years the elder and was 8 years the elder. I had my time as a new born, toddler, etc... by the time they were each born and our parents made it clear that I would not be allowed to interfere in their turn at those youngest ages. Mom and dad were also very aware that it was their job to make sure that my younger brother's did not interfere in my turn at being the older ages.  As much as possible anyway. Part of that included me being the big brother with age appropriate responsibilities for my two younger brothers.

Time to get DH on the clarity train on all of this and make sure he is doing his part.

Just my thoughts of course.

Good luck.

I am not saying that a SAHM doesn't work.. but your husband is not necessarily "roaming free" is he?  He is off earning money that provides for all 4 of you.. his three kids and you.  

Many SAHM's understand that the balance of obligations in the home can be shifted so that one is contributing financially (with the EFFORT that entails).. and the other partner may contribute by ensuring the home and kids are cared for appropriately.. .which is also work.. 

 Of course, there should be some balance to this right?  Just because he works outside the home doesn't mean he doesn't also have some obligation to spend time with all of his children and participate in their parenting.  Just because he earns all the money supporting the home shouldn't mean you don't have the ability to direct how those funds might be spent along with him.

As far as the extra work of the 8 yo... I would assume he does go to school so he wouldn't be there during the majority of the day which should hopefully give you some break.. and it's worth looking into after school activities and programs.. and even looking into occasional babysitting services for the other kids so you can get things done.. or your DH taking some time on his days off to care for his kids while you do things you need or want to do.

As others also said.. at 8 you can certainly be teaching his son to be more independent.. there should be nowhere near the same level of oversight and work needed for an 8 yo vs a 3 or 1 year old.  He can help clean his own room.. learn how to fold and put away his clothes.. make himself a snack etc.. and honestly.. feeding 3 kids lunch shouldn't really be all that bigger of a deal to warm up an extra hot dog or PBJ sandwich (and the kid learns to eat what he is fed right?)

But, yeah.. your DH doesn't get to go to work and then horde all his "free time" to go play golf or fish with his buddies while you continue to care for 3 young kids.. you share that time so you both get some breaks.  And if his job is so consuming or tiring.. perhaps you might want to consider going back to work yourself and your kids can go to daycare and both of you can do your roaming...