An oxymoron if ever there was one.

Societal standard?  Not if the Sparent has even half a brain.  IMHO

The only standard that works, IMHO, is if the Sparent sets and enforces standards of behavior and standards of performance in how they will be treated, how SKids will behave and perform when in the Sparent's home, and more importantly, makes it crystal clear to their mate that the mate will enforce those standards in partnership with the Sparent.  Both the Breeder Parent and their prior failed family spawn need clarity that there is no option but to enforce/abide by the standards or leave.

Successful blended marriages and blended families are entirely possible when the mates at the core of the blended family adventure have and maintain clarity and partnership within that structure.  The marriage thrives, the kids thrive (yours, mine & ours) and the overwhelming majority of the shit show suffered by so many blended families, and blended marriages, can be avoided.

In my layman's opinion of course.

The relationship is not dictated by societal standards I don't think.  Every situation can be different.. young kids.. adult kids.. mental health issues.. custody issues.. EX issues.. SP issues.. BP/partner issues.

I don't think that retaliatory disengagement necessarily is to prevent hurt.. though that can be a benefit.  The reality is that sometimes two people just don't have much in common or desire to build a close relationship.  A child or adult child may feel pressured to accept a "new parent".. and that can be uncomfortable for them.  A SP can feel pressured to act as a bio parent for their Skids.. again can be uncomfortable for them.  I think mutual respectful behavior should be a minimum.. but whether it goes beyond that depends upon individual situations.

Let me describe what I've seen. Those standards say we are suppose to be like a Stepford Wife. Love those SKs while not saying a word about bad behavior, letting them treat you (SM) like crap because "they are struggling with their parent's divorce, etc", to worship the BM as the All Mighty (after all, it's HER children! <eye roll>, and fuly support your SO/DH in is bowing down to BM, being her and his kids ATM and being the best Disneyland dad because the children don't "have a father" in their home. Blah. Blah. Blah.

What I've learned. There are NO standards and there is NO normal. Each situation is unique and most are not peaceful. Today, I tell anyone planning to be in a relationship with a man with kids, tread carefully. If I had it to do all over again, I would be civil and superficial. Would not try for anything deep, would only move forward with the relationship based on the child's actions, not mine. That would include both emotional and physical needs. My money would never be spent on SKs and there would be minimal sacrifice for them unless the relationship (which they led) would call for more. They aren't my kids. They have two parents. The fact that I married their dad does not give me any other postion in their lives except as their father's wife (which is how I am referred to anyway).

As it stands, I am fully disengaged from DHs crew and just celebrated my 4th year anniversary of not seeing them. Not a hard date to track since they did their ultimate humiliation of me at DHs retirement party. I do not see my disengagement as mean/hateful/payback. It is a position I've taken to separate myself from people who really don't like me and have caused me years of heartache and pain....enough years of damage to cause me severe emotional damage that took almost 3 years to heal from. I see disengagement as saving my life.

Every situation is different. People come to this forum to vent. You won't find anyone on here that DOES have a successful blended family. I would say it's definitely rare though. 

I've been a teacher for 10 years and have had MANY students with divorced families. Out of those 200+ families, only one sticks out. They both remarried and had "bonus" parents. All adults got along and steps seemed comfortable too. I honestly think this is so rare though. It requires maturity and level headedness for ALL (potentially 4) adults involved. This is even without including well adjusted SKs... (also a rarity). 

Personally, I think the "blended family" described above is what society thinks it should be. However, it's just not realistic. It is usually from people who have zero experience with the situations too. 

The first family as in skids or their parent believes original status quo maintains no matter how dysfunctional, disrespectful and unaccepting it is to the new family members.

there is a saying when you marry someone you marry their family because all the drama and dysfunction affects you. You're thrust into it whether you like it or not but dr phil once said that its the spouse/partners job to act as middleman and sort out the unacceptable family bullshit so their partner/spouse is treated with respect otherwise they have no business getting into a relationship

thinking the old status quo continues indefinitely when that first family is a failed one and divorced is insanse when the parents have remarried, have new kids etc, the family  dynamics have changed and the failed dysfunctional skids either can accept it respectfully there are certain basic standards expected of them if they wanna maintain a relationship with that parent or enter their home

i have made it extremely clear to my husband in late 2018 that we had been married 4 yrs and his kids were now actively trying to destroy our marriage, disinherit me and my kids from hubbies estate by demanding as per exwife- that hubby start transferring his assets solely to the skids name, guilt hubby for marrying me and having 2 kids with me whom hubby loves (way more than skids because our kids are respectful and pleasant to be around compared to skids), despite their cheating whore of a mum being remarried the week the divorce was finalised is ok. 

i put my foot down then and there that i would no longer remain married to him if he didn't protect us financially and ensure if anything happened to him today or tomorrow, that we wouldn't be on the streets. Hubby bought a home and put it in my name, i had made it very clear i could not and would not remain in a home with his son who was actively sabotaging and destroying the harmony of our marriage and that hubby was encouraging and allowing this to continue.

hubby

manages his relationship with skids away from me. Its been 3.5 yrs since i fully disengaged from skids. Hubby has told his eldest daughter who is now 26.5 and ss now 24 that its their choice to behave this way but they need to understand as per their own admission, bio mum is a liar, abusive, cheated and nehlected them for her affair hubby, that if my husband was not alive anymore, they have nobody to guide them except me. Because i am the only positive role model they have and they destroyed that relationship over crappy unacceptable behaviour they chose to continue and thats on them. Hubby made it clear he had a priority to protect me & our 2 minor kids from their toxic unacceptable behaviour and they seriously needed to reflect on their unacceptable behaviour - they chose not to because they still naievely think hubby would destroy our marriage to be around their miserable arses.

I don't think there are societal standards. I think you can conduct your family the way you see fit and whatever works for you. Step or intact 

Every situation is different. Some stepparents are pushy, meddling in every situation and are trying to replace a parent and then they are upset when skids start pushing back and disengage themselves from a stepparent. Disengagement works both ways. Some stepparents are kind and loving and respectful yet skids are nasty to them for no reason and either never warm up or simply being volatile. Some stepkids are nuts and some stepparents are crazy lol Some bio parents are totally screwed up and some are great.

So whatever happens in your family is very individual and subjective. Whatever you find normal, that's your normal 

i also have  to add that most (if not all) bad stepfamily situations stem not from how stepkids are but how ones spouse is. Husband or wives don't appreciate their spouse and dont prioritize them or are simply lazy and uncaring. You can't expect skids to be appreciative or even respectful in those circumstances