I quite agree with Leed.

If you don't feel a special connection with the kids, it is NOT going to work.

I am on the other side of this. I have a 7 year old, and am remarried. My hubby thinks my little girl is the best thing since sliced bread. They play together and he adores her. Albeit I am the primary carer for our family.

You however have jumped into a situation where you are the mother to his pretty much motherless child, and stepmum to his little girl. He obviously cares for his kids, and you can never come between that. Or if you did, he would be a man nobody wanted.

Unless you can care about his kids, and take them on as your own for when you have them, your relationship is doomed.

Good luck! x