It's complicated. It doesn't mean they're more important than your relationship - don't set that up in your head, because it'll only hurt. Parents want to be there for their children. If they were your children, you might feel the same. If you back him up, he'll love you for it.
But... do talk about it. Don't just swallow your pain.
I agree with all posts. to be blunt, his kids will ALWAYS be his kids. You have 8 months of history with this man. Your insecurity is apparents when asking this question. It is likely you will not be his girlfriend for long.
Figure this one out fast. Family is forever
It kind of depends on what you mean there. If he is cancelling with you because his adult daughter wants him to help her clean out her garage, then it would be a problem. But if it's something important, like his daughter is in the hospital or really needs him in some way, then I think I would understand. It's all a matter of degree. There should be a balance.
Whatever is going on, pay attention to it. If it's just because he is a devoted and caring father, that's a good. If it's because he is in some sort of codependent relationship with his children and he is at their continual beck and call, then that isn't likely to change, and it might very well indicate what any future relationship with this guy will be like for you.
I agree wiy EVERYONE WHO ANSWERED
Family. It's what is important ya know...
For me, children, no matter what the age, are top priority, and my partners always know that, and usually they have the same priority with their children.