How do you and your husband manage your finances?  Assuming that you're fairly equal earners and you don't need him to survive, I'd separate finances, do for my own kids and not allow any of my money to be used for SS. If you want to take your kids to the lake, take them.  If your husband chooses not to go because SS isn't welcome, so be it.  If you want to order takeout for your kids when SS isn't around, or take your kids out to eat without SS, go right ahead.  Your kids, and your relationship with your kids, shouldn't suffer because your DH is a guilty divorced dad.

There's absolutely nothing you can do about your MIL or the BM buying or doing things for SS.  Not everything is going to be equal, nor does it need to be. They owe your kids nothing, and they can do what they want for SS.  I wouldn't waste my time worrying about that.  But you should feel free to do for your kids without worrying about SS.  

So go without your husband too. 

I am going to try to choose my words here because I am a traditionally more "submissive" wife. I am old enough in my values that I see my husband as head of our household.

However, I was also a single mom for a long time and have experienced a lot and know my strength and worth. For a "submissive" wife to thrive, which is my husbands job to make sure that I can as head of our household, he is supposed to lift me up. Treat me with kindness and respect. Worry about my worries and help take care of my fears. 

Your husband is not being a leader to your family, he is being a dictator. I understand you wanting to make him happy but not at the cost of your children. The new kid in doesn't get dibs on any bedroom. You don't stop living your life because SS isn't there. I can see some things like, waiting until next weekend to see a movie as a family or going to a theme park, but it is still ok to do those things without him too!  Timing won't always work out, but that is why SS has 2 parents, so the other can pick up some of the slack.

It is time you take your home back. Plan this trip when you specifically know SS won't be there. Tell your husband you are doing a trip for your kids since they have not had one and SS has had several. If he doesn't want to come because SS won't be there, fine, he can stay home, but you are going with JUST your bios. 

never feel guilty for wanting to do something special with your children. If your hubby won't do it w/out his son, leave them both at home and call it a "girls weekend" 

Just do with your bios and dont let DH and lil dictator SS make you feel bad.

I feel your pain that DH cannot do anything without SS there. Its ridiculous. He is only there 50% of the time and DH expects you and your kids to rot until lil prince bragger is there.  NFW

Start enjoying life with your bios WITHOUT any of them to ruin it. Hell if you want pizza order it, chinese go for it, Disney world go have a blast. Live your life.

Frankly your DH needs to downplay the guilt , SS is already a monster , it will only get worse.

I can't get over the fact that a part-time resident demanded a full-time resident's room that she has had all of her life and actually got it! WHY? 

MOVE SS BACK INTO THE OTHER ROOM! This coddling and worship of SS needs to stop, otherwise I would kick all of them out if I were you. Go back to being a single mom, ordering pizza whenever you want and taking your kids on vacation whenever you want. I can't believe you can't go on vacation because of BM and SS. Don't do this to your kids.

You are sacrificing your own children to your DH and the shallow and polluted gene pool progeny of his failed family breeding efforts.

smh

Your DH needs to grow some balls, put his mommy in her place, and keep a belt applied to his nasty spawn's ass any time it steps out of line.

As for what SS gets to do with MIL and his own mom, that has absolutely nothing to do with anything.  Quit being envious that it has privileges. It will be a nasty adult because it is a nasty child whose nasty crap is facilitated by your ball-less DH.  Guilt is a choice. Make a different choice.  This applies to your DH as well.

Of course you know what to do. Re-read your original post as if it is someone asking you what you would do... then do that.  IMMEDIATLY!!!

When I met my DH his mother (my MIL) would tell him what to do and he did it. She would often use guilt and manipulation. She would tell him that he needed to "entertain" SSs when they were with him, that he needed to take them on fancy trips, that he needed to buy them XYZ. She definitely feels bad for them and showers them in gifts (for example, she spent $400 on one of them for Christmas this year...she spent maybe $50 for my DD (her granddaughter)). DH would be annoyed by MIL, but I don't think he realized how abnormal it was for a mother to call the shots for her grown son. I, however, enlightened him...or maybe just empowered him to ignore and push back on her. She still tries to call the shots in our home, but we ignore her. DH has had it out over with her over a few egregious issues (involving MIL meddling with BM) and MIL was insistent that she was only looking out for SSs, accused DH of not loving them enough, and refused to apologize, even though DH specifically asked for an apology. She said that DH needed to go to counseling with her, so the counselor would tell him that he was wrong. DH has said to me, "I love my mom, but I know she won't change" and he now keeps her at arm's length. MIL now goes directly to SSs whenever she wants anything, she even includes them in any planning messages about holidays. We've given up. We see her very infrequently, which is unfortunate for her, because we now have a child of our own who she would like to see, even though she treats her like she's a second-class grandchild. 

In our case, it's all about power for MIL. MIL also has some narc tendencies, which makes it easy to see why DH was not pushed away by BM's narc / borderline behavior. She showed it early, too, because he lost friends who thought she was terrible. DH has essentially lost his family because they have decided he is a terrible person for getting divorced and have believed BM's lies that she is the victim. They don't see that they've lost him (even though he has told them that he has been hurt by what they did and feels as though they never support support him), because they just assume things will keep going the way they always have been with MIL bulldozing everyone, BIL as the golden child doing her bidding, and DH off as the scapegoat. 

Dealing with someone else's dysfunction is never fun or easy, but if your DH can't see the havoc his mother is wreaking on his home and his life, it will be difficult for you to change this situation. 

I am big on things NOT always being equal and fair for my BK's. It's called life. IMO, comparing yourself to other's and keeping a tally is the thief of joy. My BK's all have a different role in the family. Things are not even close to equal as each has their own unique strengths, needs, and developmental level. As long as there is mutual respect and love, give without the expectation of anything in return.

BM is the opposite. She makes a huge deal about how her princesses have to have everything be perfectly equal, little petty checklists of everything with each other and with their Father, and of course if it were up to her, the princess would have far more than me and my BK's. (Meanwhile she is super lazy ... she needs copious amounts of "me" time and does whatever she wants whenever she wants it all the while telling DH that he's "on" with entertaining and caring for the step-diablas ...  In other words, not at all equal.)

She demands her princesses have equal alone time with parents, equal possessions, equal say to their parents, equal position to their parents, equal portions of salad, or whatever ... It's so stupid, dysfunctional and childish.

It seems those most insistant that everything be "equal" really have a chip on their shoulder and feel inferior. They need more to feed their need for constant validation that their position is secure. It's a primitaive, insecure, way of living.

My DH was so accustomed to BM's disfunction ... it took awhile for him to shed some of that ignorant mentality but he's a lot better about it now and not trying to keep everything "even steven." Now that SDiablias are grown he doesn't give a crap about BM's demands.

Time to put some boundaries in YOUR HOME!

A minor child in my home does not get to decide what and where and how we go/do /say children are at the whim of adults not the other way. Wether that child is BIO or not. ) Wether that child takes the form of a husband or not! Lol)

I have never heard of " BM handles the summer schedule" ever. But the BMs in my life cannot handle ANY schedule so maybe that's why?. IMO that's BS meant to manipulate you on DH behalf.

Your parents are wrong. Your kids in this situation should come first. They wouldn't tolerate SS behavior from a neighbor kid who hangs out at your house would they? Or from their neighbor who demands the best for their manipulative spoiled brat! Bless them for trying to make you a cohesive unit but they shouldn't be involved in SS life in the first place.

DH has manipulated you into giving SS your daughter's room? That is strike one! If I like you you get three lol.

I have dealt with an MIL such as what you have( I can't say worse because I don't know your MIL.. It culminated in me kicking her unannounced ass out while she was reading obituaries in my living room. Long story lol- yes I only laugh because she is far away in a different state)

The ace in the hole is that DH is in your house. Think about that....

Book that trip go without DH. Unless you are afraid to let DH and SS alone inside your house, in which case this needs to be an entirely different conversation.