Hi S.:
Oh how I feel for you. I understand being in your situation. Love doesn't just happen, especially when there are so many other situations getting in the way...
Please forgive me for saying this, but, your husband is only seeing what he really wants, and that is he just wants everyone to be happy and loving.
The children; of course they are coming between you and your husband. That is their daddy and I am sure they must miss him very much. I'll bet they think that YOU are getting in their way, too!:0)
With all that being said, this is what seemed to work for me. It sounds like my situation was a bit different, though, because my former love had only one child. I made 'special' time for only me and the child. She and I talked about what we thought would be fun to do and it was OUR thing. We signed her up for dance classes once a week. I picked her up from her mom's house, we went to dinner, then dance class. Maybe on a really nice evening, we would stop for ice cream after. What goes along with dance class? Dance clothes! All of this made for opportunities for us to talk, which made us closer. I learned what was going on at school, her teachers names, friends names (the ones that were the most important to her), her favorite colors, I learned all about her mom's side of the family, etc. Remember, this is long term.
After all this regularly scheduled time together, just the two of us, I knew her better than her dad! It gave us lots and lots to talk about.
Do the children have their own space at your home? I made Paige her own bedroom at our home, which came with her own toys and clothes. She had her very own space to go to when she needed her space. It made her feel like I really did care about her, because I took the time to really make it all about her. I went a little over board; I found a comforter in her favorite colors, then painted each wall in her bedroom one of those colors (4 in all). Can you imagine her surprise when she saw her bedroom for the first time?
How about getting a 'family' pet that everyone picks out together? Having one common interest can help.
Do you make a big deal out of the holidays for the kids? Meaning, do you make sure to do things for them that their own mom does? Easter baskets at Easter? Stockings at Christmas? In other words, do you think of them as you would your own children?
Do you know what each child's favorite food is? Do you make an attempt to make a dish for each child?
As they see it, you took their dad away from them. That's just the way kids think. You have him and they don't. They WANT you to love them, too. They just want to feel like they belong at daddy's house. Not like they are just visitors. They NEED to feel that they are part of your family, not just part-timers.
Speaking of which, do the children know your family? Do they see them on a regular basis? Are they feeling like they are fitting in there? There are no exclusions or separations when it comes to step-children. Not allowed.;0)
I'm sorry this is so long. It's just that I've been there. Both with being the step-mom and having a step-mom who basically rejected me is so many blatant ways. I know how it feels to not belong with my own dad. I also know how much fun you can make it to draw your step-children closer.
Who knows? Maybe you and your step-daughter have a common love of books or shopping. Maybe you and your step-son love to play catch or walk the dog, or play Lego's????
Don't put too much pressure on yourself. It will all happen in time. Have fun with your new family. You will get there.