If its affecting you, yes. Otherwise no. And by affecting you I mean like I'd they're ruining stuff in your house, etc. 

Its called disenagement. Also, some wise person on here said words to live by. "You can't care more than the bio-parents." and the other one I tell myself is Not my circus not my monkey.  They are DH kids not yours. I would stop doing anything, and claim you are just too tired. 

Do what you need for you and your DH depending on your financial arrangement.  But doing things for people who laugh at you?  You have got to be kidding.  No laundry, rides, or foods/snacks that they like at the grocery.  If they make a mess in a common area then it stays there.  If your DH is not home for a meal then you don't cook.  Just have something that you can snack on in your room or eat before you come home.  They can have cereal.  When they start treating you with respect then you can start to slowly do things as you see fit.  Until then they are on their own.

You shouldn't care about their behavior more than their parents. In that regard I wouldn't be bothered until it affects you. 
 

Only do the things for them that you want, if they need something direct them to their father. It really depends on how big of a hill to die on it is for you. If it is let your hubby know he needs to enforce chores if he doesn't he can wake up from his slumber to be their chofer or their mom can pick them up. 
 

You are allowed to be fed up, don't let him invalidate your feelings. Good luck 

There is no way in hell I'd spend my life parenting and cleaning up after someone else's kids while he sleeps or does nothing. 

Nope. 

If they aren't going to do it, and your dh won't either, you can demand he pays for a maid/babysitter for his kids until he comes home.

These girls are NOT your responsiibility. PERIOD. 
They are the responsiblity of your H. Yes, I purposely left off the 'D'. He needs to get a job that fits their schedule. WTH would he do if YOU were not available to play chauffeur and skid-sitter? He'd either get a job with different hours OR they'd be at BM's. 

Stop doing stuff for them!
They are 12 and 14. They should be able to do their own laundry. They should be able to make something to eat. 

Your husband is a YUGE part of the problem.
He's not there to parent HIS kids. 
His poor parenting is the reason for their craptastic behavior. 

NOT your circus; NOT your monkeys. I would die on this hill.

Ain't that much love in the world where I'll run myself ragged for disrespectful H and kids. Your health has been impacted from all the sacrifice and running around you're doing. Let it all go! Leave it for your H and BM to deal with since they are THEIR children and call it a day.

Only you can stop this madness, no one else.

What are you getting out of this relationship? I would never ever do what you are doing!

My DH tends to be a passive parent (in part because parenting is hard work, in part because he's afraid SSs won't want to come around). BM does everything in her power to make sure that SSs never face any obstacles or have to do anything they don't want to do. I used to try to parent them (e.g. make sure they brushed their teeth, didn't play on their phones all night, didn't watch inappropriate thing on television, did their homework), but then I realized that I was the only one who said these things to them, so it was a losing battle. They always have toothbrushes, toothpaste, soap, shampoo, and towels in their bathroom, but I don't try to make them use them. They know that I read a lot and that I believe people should do all their homework, but I don't say it to them. They know that I expect everyone to clean up their own trash. But I no longer try to enforce these things, because it's not worth my energy. If they turn out terrible, no one will blame the stepmother (actually, people usually blame stepmothers for everything...). 

Also, I told my DH that if he didn't want his kids to pick up their own trash or put their dishes away, that was fine, but I expect him to do it and I expect him to do it before I even notice. I also don't babysit. I used to do a lot of stepping in to watch DH's kids when he wanted to do something else. Now, I tell him no, that's his responsibility. This is largely because I was receiving zero appreciation for my help and was usually receiving a lot of snide comments and criticism from BM (because SSs are tattletales and would go home and say they were with me, not DH and she would offer her opinions on that). So, no, now I stay out of it. DH complained this weekend that he wanted to work overtime and couldn't. I told him that yes, it would be nice to have the extra money from overtime, but I was done being his babysitter and done putting up with complaints and comments from SSs, BM, DH's family, so he has to manage his weekends with his children. 

The life of a stepmother is challenging enough...it's even more challenging when no one appreciates your efforts and when you are taken advantage of. 

Excellent advice here. My addition is to step way back and make yourself less available. Let your work be the bad guy and say they changed your schedule and that you'll no longer be able to do the driving.  Guess their actual PARENTS will have to figure that out.  Go to the gym after work, do some kind of recertification thing even if it's bogus, volunteer, anything but be the unpaid, unappreciated nanny/slave.  

Realize that you have said yes to all of this and are enabling it.  You're allowing your DH to work, sleep and shirk his parenting duties.  Quit picking up his slack.  

Do you want this marriage?

You wrote that you are the breadwinner and DH is working part time at a restaurant.  You didn't mention how many years you have been married to DH but you might take a look at your marriage.  I don't mean to be insulting but this really sounds familiar.

When I married DH he had just changed careers.  He was not quite honest about how much he was making or the what the future offered in his new job.  I was the breadwinner for years.  I did my best to try to make SD like me - she treated me like dog doo and would not lift her finger to put a dish in the sink.  I did all of the work.   I provided health insurance, a place she could come to visit DH, and at least 1/2 of her entertainment funds.  When Dh was home he sat on his ass and I waited on both of them but was pretty much invisible - never appreciated for what I did.  DH never expected SD to respect me as his wife.

Several people have advised you let DH take care of SD's needs - ALL of it - including paying for for what they eat, entertainment, everything.  Do not spend another dime on them or another minute of your time being a servant to them.  Your DH must insist they respect you and clean up after themselves.  If he can't do this, step back and take a long look at this situation and if there is a mutual benefit to staying married to this man.

Seperate yourself and dont clean up after them. Thats what i do. I stopped cleaning up after my step son cause he is more than capable of doing it himself.