Blended families

I’m newly married and I have 7 kids with three of them age older. 15,17,21. My husband has 6. So yes together we are a big family….. so the issue is my older kids don’t speak like say hello and he’s doesn’t either. I really feel like he’s a grown man and he should say hello Frist. I have talk to my kids and the speak and then it goes back to he’s not speaking so my kids don’t..I’m really exhausted about this whole situation. I also feel like let things come on them..