I think with Bethenny and Jason, it may not be an issue of expecting the other to change, but rather expecting their repsonse to change to be different. I think that Jason's values said that when you have children, you slow down your life to focus on them, and assumed Bethenny felt the same way. I think he also assumed that he enjoyed being with his parents and being close to family, so she did too. And, I think that Bethenny assumed that Jason's interest in her business meant he wanted to be a part of it. Each of them made assumptions that based on what they knew, the other would respond to certain changes in their lives in ways that are different than what actually happened. We also can't forget that their entire courtship and marriage was sped up by the surprise that was Bryn, which probably also altered the decisions they made.