Val, you know from my own sitch that I too experience the many moments of p!ssiness and rampant selfishness.
In my opinion, after years of our co-dependent behavior, we get to the point where we spoil them rotten. We make pleasing them and avoiding conflict our main mission in life. However, rather than making them happy, it only engenders disrespect and disdain for us in their minds.
Now that we're our own free agents who make only the decisions that are right for us alone, they become p!ssy. It seems to me that they never expect that we will buck against their wishes after they leave. Probably never was in the game plan when they drew it out, really. (Did they just think that they'd get to have it all, no matter the circumstances?)