David and his parents enjoy generally good relations--not perfectly harmonious, mind you, but pretty good. There are mistakes and tensions on each side, from time to time but these are usually repaired. Misunderstandings are usually cleared up. Nevertheless, his parents are sure that David has some longer-standing complaints about his parents. His father, as an example, is distinctly weird.
David, of late, has been struggling to establish his own realm, a bubble of privacy, under difficult circumstances. He does not have his own room, cannot easily go anywhere to be alone. He needs to feel separate, somehow; needs to get some distance from his parents. He needs some way to assert his distinctness. His parents are pretty sure that one way David has of drawing a line is to share complaints about them (relatively minor complaints, they hope) with his friends. His friends, perhaps, sympathize. They know his parents through David's accounts, have very little personal contact, and have formed their opinions largely through him.
Now David is on a class trip to Washington on which his mother is serving as one of the chaperones. A problem has developed.
David's friends, in extended contact with his mother for the first time, appear to be drawing the conclusion that she is cool. Some of David's complaints seem to be losing a measure of credibility.
Don't worry, son. Your Dad's still weird.