It sounds as if most of your disagreements are around finances, which can be a tricky area unless you are both on the same page.   However it would be helpful if you could be more specific?  are you proposing to pay your kids college fees (or paid, as regards the 24 yr old) and he disapproves? 

Personally, I think kids should pay for their own car, and should only have one if they pay the running costs through a paid job, but then I am in the UK and we have slightly different attitudes towards this kind of thing.  Kids here mostly get a student loan from the government to pay college fees.  

WHAT? Are you really saying that Stepdad has final say on if his step kid gets a car? Stepdad is more important to that skid than the actual parents? Nope no way.

I see no problem with her and her EX getting their kid a car if they so choose. Every had different opinion on this and neither is wrong. He sounds like a good kid and if THEY want to get their kid a car, stepdad should have absolutely NO say in it at all. AS LONG AS THEY ARE NOT ASKING SDad FOR MONEY TO DO IT.

OP...Tell DH to worry about his kids and you will worry about yours.

different parental styles, parental involvement and support.

My parents fully intended on paying for college for me and my younger brother.  They did end up paying for 4 years for both of us.  Since I was on the 11yr undergrad plan... I paid for the middle 7 years.  After my first two years of hopping majors, girls, ski slopes, and beer drinking institutions they handed the college bills to me to pay.  And I did... for 7 years.  6 of those I worked full time (started and ran my own company) and went to school full time. The 7th year I lived and paid for school on the proceeds of the sale of my company and from my divorce.  Since my younger brother joined me for engineering school our parents graciously paid for my last two years of undergrad studies since he and I lived together, went to school together and were in the same study groups and classes.  Though I did work full time to cover as much of the costs as I could.

While I understand your DH's thoughts on it being his home, his wife and his marriage/family the fact is that you and he have blended much older children from two very different parenting and socio economic paradigms so it very well may take a very different approach for your kids as compared to his. 

My wife and I come from very different family and socio economic backgrounds very similar to what you describe is the case for your DH and yourself.  My family has always been very focused on education and professional career performance while my IL clan are generally HS educated unskilled agricultural laborer types.  With the exception of my mutant dual major undergrad/MBA/CPA bride. My FIL does have an AS in Agriculture and Animal Husbandry but generally worked as an Ag laborer for most of his career.  He has a problem with authority and is one of those who knows far more than his bosses which has been a severe limiter to his opportunities for advancement.   His three BKs, my bride's three younger sibs (half), are following the model that he and my MIL have set as the example.

My bride and I raised SS with a focus on education, analytical thinking, problem solving and on character development.  We had every intention of providing the full meal deal mom and dad scholarship to SS for his college.... he made a different choice though. Interestingly he chose a different path than his mom and I followed (we both went on to college, grad school, professional certifications/careers) and enlisted in the USAF.  He is working on his BSCS though a bit slower than his mom and I would like.  He is doing great in his  USAF career and intends to do 20+ and make it a career.  Since he enlisted at 18yo he could very well retire before he is 40 and launch a private sector career. His AFCS is one with very good translation to the private sector. In 9 days he will compete 7 years in the USAF.  He is in Germany for three more years then indicates that he will re-enlist and push for retirement at 20-is years of service.

We shall see what he decides as his life continues to unfold.

Since he, the USAF and our fellow tax payers let us off of the hood for his college education we bought him a new car as a combination HS graduation, Christmas, Enlistment gift. We figured that was the last thing we could provide for him as he launched into his adult life on his own terms.  That car is now in Germany tearing up the Autobahn.  I have a feeling that it won't make it back to the States when he finishes his Germany assignment in 2021.  That little turd had better not bring back a cool sports car before I get another one. 

*aggressive* 

I needed a combination of support and forced accountability to effectively manage my college journey. My bride was on LASER focus and needed zero external motivation or support. Before we met and married (the last semester of my 11yr plan and her first semester out of HS) she was paying for her school on her VA survivor benefits from her bio dad and with loans.  Her BioDad was killed in a car accident while he was serving in the US ARMY stationed in Germany. He died before my MIL knew she was pregnant.  If I had not entered the picture it likely would have made zero difference on her college success she is that focused and scary smart.  Her mom and dad (Step.. he was in the delivery room when she was born and is her Daddy) did not have the financial resources to help her with college. And wouldn't have helped even if they cold have. Their self stated delusion is that they raise their children to be self sufficient adults at 18.  My DW is eldest and the only of their 4 children who have attained full fledged adulthood and the youngest is now 31. My MIL and FIL have yet to attain full fledged adult hood and manage their lives in an eternal quest for instant gratification rather than as measured goal progression focused adults. 

Each family is different with unique parenting models, each kid is different with different needs.

In the case you describe I think that communication between  you and your DH is key.  He may not agree with how  you are raising your own children when it comes to higher education and  you may not adjust according to his inputs... However, the respectful discussion is critical to make sure the two of you are servicing  your relationship effectively as equity life partners.

IMHO of course.

Good luck.

Bite your lip GoodLuck, bite your lip. NOPE cant do it.

Miss, My family until I was 18 was a conservitive old fashion family. Dad worked, mom was home with us kids. My dad made an "above"  decent salary and was college educated. His job took him all over the world. I still have the post cards from Egypt, Spain, Morraco, Mexico City, England, Japan. No he was not military.  He had company cars, expense accounts anyway,,,we spent summers at the shore.

The day we ALL turned 15 my dad gave us the SAME story,,,,,fill out your working papers and start working somewhere part time, keep it within walking distance....AND we did. We didnt have a choice. We kept our earnings and stuck them in the bank and spent very little on ourselves.

Most kids my age had jobs. The girls were waitress at local diners.  The  boys in my town saved their money to get cars. Parents did NOT buy them...no way.  THEN if they wanted to go to college they worked and went to classes. OR they found jobs or stayed working at the place they started at age 16. IF you were fortunate to have a scholorship you were lucky otherwise it was student loans. And we were expected to pay them back. We most certainly did. We didnt ask our parents for money, they had their own bills to pay. Frankly many people my age wouldnt have the balls to. 

I say all this because it seems like your SO and you are on seperate sheets of paper about the kids and HOW you  are giving them most everything....just like your parents gave to you. Your words not mine. 

This will be an ongoing problem, unfortuantly. YES you can spend all your money on your kids if you want to. And he has different ideas and I have to say, if his ideas are, hard work and pay for what you want....I must say I agree with him. Remember op, my dad made a very good wage and WE were not given everything, not by a long shot. We worked for what we had.  

Thank you Dad and Mom....

Dupe

OP, there is a similar dynamic in my marriage.  My wife was a single mother most of her adult life.  She has two sons who are now adults.  Her boys have different fathers.  She had to work multiple jobs most of the time to provide for her kids.  When she was with someone, they typically used her for what she could provide them, and then tossed her aside.  Neither of her sons are very motivated.  I get along great with her oldest son, but have nothing to do with her youngest.  He dropped out of high school, became a pretty serious drug user, and hasn't really ever held down a job.  He may be starting to get his head out of his butt, though.  Time will tell on that.  Because my wife had to handle everything while her boys were growing up, her tendency is to jump in and micromanage every aspect of her adults kids' lives, as much as they'll let her.  Her sons are both technically men, but often don't know what to do in life without mom telling them how to live.  Neither one of their fathers have been much of a positive influence in their lives.  They've never been taught how to be men.  They've relied on their mother to guide them in life, even into their adulthood.  Neither have the internal drive to pursue college or to do the hard work necessary to pull themselves out of their position in life.  They're coasting, at best, and seem ok with that.  The oldest has tried a bit of college here and there, but his heart just isn't in it.  My wife spends a lot of time obsessing about her sons.  Her youngest has been horrible to me.  I don't have a relationship with him at all now.  I genuinely love her oldest boy, though, and enjoy spending time with him.  Because of the situation these boys were raised in, things were always very tight financially while they were growing up.  My wife simply didn't have the means to put them through college, to buy them the latest fashion, or other things a lot of kids take for granted.  She did the best she could, but didn't really ever have very much money while they were growing up.  It bothers her to see how they are now, and she feels responsible for the way their lives are turning out.  They're grown men, though, and are making their own choices. 

My wife and I have been married for about 3 years.  I make a very good living.  I have two sons who are 13 and 16.  I've instilled a good work ethic in both of my kids.  My oldest has had a part time job since he was 15.  He's a year ahead in school, and will finish high school at 17 with both a diploma and an associate's degree.  I've taken him to visit college campuses, and he knows exactly where he wants to go already.  He's currently 4th in his class.  He's very driven, and knows what he wants to do.  I just hooked my 13 year old up with a summer job mowing grass for a friend of mine.  He's was on the jr high track team this spring, as well as the choir group at his school.  He is a confident kid, but he does have a bit of a lazy streak sometimes.  I got him the summer job to work on that.  If he doesn't do a good job mowing grass, I'll make him do it again until he has done a good job. 

I expect that I'll need to chip in here and there to help both of my boys with college expenses.  I haven't committed to doing that with them, though, and want them to try to figure things out for themselves first.  I imagine that when my boys get to their college years, the amount I will be able to help them will bother my wife.  She wasn't able to help her boys in that way, and I think she feels a lof of guilt about that.  For some reason, I expect we'll have some pretty contentious discussions when the time comes about my boys having advantages that hers never had.  I think that my ability to be there for them in that way will really bother her.  I'm a good dad to my boys.  She sees how I am with them, and it bothers her that her sons never had a dad in their lives that way.  

My wife and I have known each other since we were kids, but our lives took very different paths after high school.  Somehow, we found each other again.  The way our kids were raised, or are being raised, has been very different during those intervening years, though.  I was in a 20-year marriage that fell apart about 6 years ago.  My wife has never really had a "true" partnership with anyone, until me.  The men she has been with have used her and tossed her aside, and her kids' lives were fairly unstable while they were growing up.  My kids have had a pretty stable upbringing, even though their parents have divorced.  I've never stopped being there for them.  I think my kids have a very different outlook on life than my wife's boys do, and will probably have very different outcomes as adults.         

All your kids are adults and have their own set of biological parents.  For the most part.. these kids are 'raised" and really should view you and your DH as their parent's spouse.

You should both ideally have separate finances.  That doesn't mean you don't have common financial goals and don't agree to discuss large expenditures that can have even an indirect impact on the other spouse.

What this means is you don't get to spend on your kids buying cars and paying tuition if it means you won't have sufficient funds set aside when you and your DH have decided you will retire.  Your DH doesn't end up paying a larger share of household bills so you can lavish your kids. (not saying that you are doing this.. just that for avoidance of doubt.. you shouldn't).  As long as your spending doesn't impact joint plans for vacations and major purchases.. or even paying day to day bills.. it's really a matter of.. honey, these are my kids and I will raise them the way I see fit... including financial issues.  You are free to do the same with yours.  As long as we agree and meet our financial goals then what we do with our discretionary money is our decision.

It's not like you are forcing him to accept your adult kids moving back home.. or making him pay for their education.