Redefine your idea of "quality time." Quality doesn't have to mean expensive, intense, or uninterrupted attention. Instead, quality comes with becoming comfortable with each other.
For some children, divorce calls into question the very nature of parental love. The child may think to himself, "If my parents can decide they don't love each other anymore, maybe they can stop loving me."
My cheerfulness sounds forced to me as I chatter incessantly on the way to the airport. There is little traffic, and for once, I wish for a delay, just a short delay so I can sit beside my son a little longer.