How could you possibly know what you were signing up for before experiencing it before hand? 

thats like telling you its going to hurt to give birth then finding out what hurt really means

relax- detach- refer to dad - if dads going to pretend that you are equals with the skids, pretend that you are an annoyed older sister and roll your eyes when they are annoying, go into the other room and paint your nails 

I agree with Futuro! You and your hubs need to sit down and discuss what this will look like. What are the rules going to be? What are the chores going to be? What authority are you going to have? What consequences will look like?

Also, what does BM say about this? Has she agreed to consider it? A judge isn't going to uproot kids and move them in with the other parent because "we have no rules at Daddy's house". There has to be real reasons for kids to move if BM wants them to stay with here and that has been the status quo. 

heres another one- store all of your cherished items, really simplify your life so if your stuff gets destroyed, you wont care or be offended- furnish your home with second hand stuff. Then really let go and let Dh feel all the responsibility every bad or uncomfortable situation can be met with  "HA, HA, HA! OH, I LOVE YOU GUYS!" or   "How should I know, Ask Dad?" just like a big sister would say. big sister doesnt care that someone made a mess in the kitchen or is making toot noises for an hour, she just laughs nervously and walks away and shuts her door and lets dad take care of it. if thats how dad is treating you, let him be the dad for real

NO CUSTODY CHANGES WITHOUT THOROUGH DISCUSSIONS!

• Rules and expectations (scholastic & behavioral) must be drawn up in advance, including discipline strategies.
• DH will be responsible for ALL care and parenting. Your role is just to support him.
• BM MUST pay support, and the change must be recorded through the courts.
• Discuss finances thoroughly. Not one dime of your $ should go to skids' support, and your monthly household contribution should decrease proportionately.
• No ping ponging. Parents and skids must commit to the change for X amount of time, be it a semester, a term, or a year before a change can be considered.
• Protect your own interests!

Say NO.  What ever you discussed with SO is not going to be in force, you know it.  You will either have to put up with the misery , or leave the marrage.  Think, they will be there 14/7. No alone time, no going out for dinner, no doing anything alone with DH,  because if you leave them alone they will go wild in your home.  There a reason BM wants to get ride of them and lose CS, and pay CS on top of the money she is losing. 

I got married in July of 2018.

Congratulations! We did too. And it feels like its been all uphill. As far as increase in work, new child support orders, more toxicity from BM and NOW Feral Eldesst who just moved in with ToxicTroll, and bumped Munchkin out of her room. We had been together about 4 years.

so I knew what I was signing up for when it came to the kids. At least I thought I knew. I've been warned before how hard it would be and prior to getting married I readily accepted the responsibility.

Honey, NO ONE knows what they are signing up for. There is absolutely no one - excluding someone who has gone through this, that could possibly even imagine what this is going to be like for you. Its all the same BS for us here at Steptalk. So greetings! 

However, things changed drastically after marriage and spending time with his kids.

Sorry, honeymoon is officially over. Sounds kind of like he sucked you in because he needed a free babysitter and someone to help contribute to raising his "special snowflake spawns"!

The smaller one has no manners.  He's rude and obnoxious and his father does nothing about it.

I have two precious SD's, one Feral Eldest, went no contact for about 1.5 years. VERY peaceful. they get worse with age, btw. IF they are bad now, they get worse. Lucky for you they are both boys, because it seems like us stepmosters, er stepmothers, somehow have it worse with the girls. They get to compete with children for dadees attention, and hate you for simply existing. Munchkin SD12 thinks of me as her second mom, which is awesome. Shes really great, but entering the teen years. So I will be disengaging for like 5 years or so. "ask your father, you arent my kid..." will be my mantra. Munchkins table manners are atrocious, but shes not rude. Eldest was the fraking rudest Ive had to deal with, not to mention the patahlogical lies, and false accusations. 

They have been living with their mother and step father since their BP got a divorce. Now after just 4 months of getting married they want to come and live with us because they think they will get to do all the things they don't get to do by their mother since their father allows them to do anything they want. I love their father I just don't know if I am willing to take up this extra responsibility. It's keeping me up at night, it's making me lose my mind...any advice on what to do? 

Lucky you, you have been sucked in to their mess to clean up after them, be the maid, chauffeur, baby sitter, police, and bed warmer. Congratulations you won the step-child lottery! dont want to claim your prize? Oh well, then you must join the disengagement club Have "ask your father" tatooed on your forehead (henna). Just kidding, sort of. 

My advice would be to really have a talk, but keep in mind that if your DH is not on board completely, and not supportive, then you will be dead in the water, trying to bail out a sinking ship. Watch how he reacts. I would say tell him no, but I dont know how realistic that is. Keep us posted!

Hmmmm,,,,when bm figures it out that she wont get a child support check I DOUBT she will just give it up.

Also, she will give up more likely than not, the tax credits for the kids. Unless she passes tax credits to other people which is against the law.

You have to find out what drives bm's train. If it is money---the kids will stay with her you can count on that.

JMO