Hi Shootingstar. That was a great question. I'm going to handle the easy part first.
A contract is a legal obligation entered into by all parties hopefully with their eyes wide open and everyone knowing before hand exactly what is expected.
An expectation is different. An expectation is like a barbed hook that is embedded in the flesh. It isn't always clear to all the parties what the expectations are and are often vague, like love, honor and cherish. When an expectation isn't met the hook digs deeper causing suffering.
The big problem is that we plant the hook in our own bodies and when the suffering begins because of the unmet expectation the suffering is ours.
We have basically two choices here. We can continue to suffer demanding the other person meets our expectation and continue to suffer.
Or, we can remove the hook, recognize that this person is incapable of meeting our needs and move on. Doing this ends or at least lessens our suffering.
The first is a form of control, trying to force another person to change and meet our standards. The second is simply seeing reality as it is.
Your friend,