It was cold and dark dipper didn't know what to do until a all to familiar yellow gleam came from the creases of the door " oh god...."

The word "baby" has been thrown around several times after they married. Mostly by Mabel. Of course, it's not humanly possible for Dipper to conceive but Bill was something else. Dipper wants a baby and Bill makes a deal. In other words the progress of having a baby. Part 2: They Gave Me A Journal