Second, as his wife, be honest with your husband about how you feel, your real fears, and your desire to set some boundaries around their relationship.
Just because you both say "I do" doesn't mean all of this will automatically go away.
Bonnie's Question: Like the question I just read, I am dealing with an ex-girlfriend.
If you want a closer relationship with the sisters or others, stop waiting for it to happen and create it. OR, you can choose to let go and create your own healthy relationships in your own way.
Let go of what you think the relationship should be with the x, and begin to create what you truly want.
I'm guessing it's the latter, and after 10 years of marriage, I would love to support you in moving beyond them.