He is putting his children first, which is really as it should be. I'm sure you wouldn't like him or be as attracted to him if he were a 'deadbeat' Dad. This does not mean that there isn't room in his life for you too... I would back off a bit and not offer again to buy a bigger house. It sounds like you've found a good man.
Best wishes.
I'm sorry to say - I see this as Your problem - something You need to work on and resolve within YourSelf.
His Children are and should be His priority and it's typical for Children who don't have Their Father in the home to want to spend time exclusively with Their Dad when They can. It doesn't mean They don't like You but They do like/want and need Him more than You.
I commend Him putting His Children First and Foremost. You would want Your Childrens' Father to do the same so You need to appreciate that sensitivity in Him.
and Their Mothers' feeling about Them all staying in Your small home is an important consideration. We don't want Mom unhappy with the situation - the kids WILL be caught in the middle of that.
I agree with SpecialMom
Good Luck
Hi there and welcome. It is always hard to blend families. I wish it were easier for people. I understand you are hurt and I'm sorry about that.
But I would try to put that aside. If his kids only get to see their dad on occasion through their visitation (even if that is one or two nights a week or every other weekend. . . to them it feels like it is on occasion)-- then, they are letting dad and you know that they want time with just him. They are not wanting the big, blended family time. There dad is letting you know that his priority is them and that he too sees that giving them this time is valuable.
They don't want to share him with you and your kids. You have only been together one year which is not a long time and living together for 9 months means you almost immediately moved in together!! That didn't let the relationship build and grow between all of you.
What does your boyfriend say about this? He obviously sees value in 'his' time with his own kids at his place. His kids and their feelings are his priority and I'm not going to argue with that just as your kids and their feelings should be your priority over a new man and his children.
Perhaps down the road he will want to blend the families a bit more. For now, what he is doing works for him. His kids are happier and comfortable and all you are missing out on are the nights he's got his kids. I'd let it go and allow them to work it out at their own pace. Otherwise, you will end up having them resent you and you don't want that. Let them warm up on their own. good luck