How do you know that your H isn't missing you and D? I often think they are missing their families and just trying to keep themselves as busy as possible so they don't have to think about it.. 'cause I know in the beginning my H hated thinking about us because he felt guilty.. so he did whatever he could to busy himself so he wouldn't feel guilty.. but he said it still caught up with him.
I too feel like my H seems settled in his new role as part-time Dad and part-time friend to me... but by DBing I know that I'm handling this better than I would be if I hadn't ever picked up the book. I'm not sure how long you've been DBing but sometimes it takes a bit of time to see any results. If you've given it a few weeks and aren't seeing anything than it may be time to try another technique. But going dark doesn't work very well when you have a child..