Co parenting with another family of two kids

Hi

My spouse and I have been together three years. We have a one year old daughter together. I have two other girls a three in a half year old and a seven year old while he has a six year old son and a seven in a half year old girl.

We seem to always collide when it come to his kids and mine kids (like competition) when they are together and when they aren’t together. Like if his kids aren’t here my kids can’t play with some of there toys or none at all but when his kids are here and my oldest is at her dads they are aloud to basically do what ever they want! It seems to get the best in our relationship and makes us drift for a while. Then there been comment like I’m glad my daughter is so smart and has a head on her shoulder and then I reply back as why do u do that my daughter isn’t dumb he’s like she so ditzy and dosentthink but in reality his daughter acts like she 16 acts like an adult and thinks she can talk and run over every body and dress like she trying to get guys attention and now my daughter is doing it! My daughter has a mouth on her but not like his daughter! But here’s the thing how do you get thru this how do you try to see eye to eye with each other about this stuff when does it end of feeling like competition

I don’t like fighting or arguing about whose better or whose got it all or whose more grown so they can do certain things but the other can’t it’s not equal with them all and they are all about in the same age range