DD is 14.  She and I talk often about how challenging it is to have the skids in our lives.  She needs the validation from me that it's OK not to like them.

I get along well with my H's 28 year old son. At one point in time I "thought" all was well with the 27 year old daughter, until a few years ago it all came to a head but to answer your question.....Yes my kids are well aware of how I feel about my Hs children. They respect it and support me in my decision.

As long as my sons know I'm good they don't even entertain my H's daughters nonsense.

My kids dont live with us and never have. Im happy for that. I wouldnt put my kids in this situation with these monsters. I would'vehad to move out. They know a little but I don't tell them how bad it is. They see on their own what entitled assholes they are.  It speaks for itself. 

My OSS19 drives my kids crazy and they fight all the time but at the same time they are all protective of eachother when we are outside of the house. At this point both my bios and SS19 are disgusted by SS15. None of them care if they ever see him again. 

Do my bios know how I feel about SD23 and SD24? you bet they do!  I spent literally a decade bending DD37's ear about their iniquities - she always gave me good, common sense counsel about matters to do with them.   DD37 and DD35 rarely meet the SDs - very occasionally at Xmas and once at DD37's house in the north of England when I was visiting her, and DH had taken the SDs to visit their grandmother who lives nearby.  I think my DDs view the SDs as an alien species - ie rather alarming, but fortunately they don't have to have much to do with them.  

My kids are too young to figure it out, but I assume they will know as they get older.

Yes and my bios don't like Spawn either. Spawn and her friends picked on my son and she has hurt my son physically in the past. BD was very young and looked up to Spawn and was sad when she moved out, but recently she has told us things that Spawn would to do her, and told us how she was mean to her when we weren't around. That alone is enough for me never to speak to her again.

Due to their ages (4 and almost 6), I don’t think so? 

They inevitably will one day, though, because kids are keenly aware.

Both my D's (12 and 19) are aware, as we discuss things between us on the rare occasion we have time without the skids. My 12-year-old is having the hardest time adjusting, so sometimes she needs to know that I struggle in order to feel that she's not alone. I don't go into the extent of how I feel, but they both are aware. 

Why do you ask?

Do yours?

Only one of mine knows - but my kids and myself are over trying the "blended family" stuff.  Mine don't care to have relationships with them anymore.  They tried to be nice and only received a cold shoulder.  So as far as I am concerned I don't care either.  I enjoy being with my children and grandchildren - I am kind and respectful when I am around DH's children but that is as far as it goes.  Does it hurt?  At times - yes it does but my heart is getting harder.  

We got together when our were 5 elementary age.  I never badmouthed my ex, his ex or the stepkids to my kids.  But they were and are both empathetic enough to understand.  Once the SKs moved in a few years later, we all had an "Us against the world" mindset.  The SKs were individually sometimes pitas but sometimes, my bios were, too. We all lived too closely for too long not to know how each other felt about one another.  Still do.