Have you asked your son if your behavior towards his father has been bothering him? I know it's hard, but maybe he was bothered with how he sees you reacting. Have you talked to your H directly about your son?
I understand you're staying dark or whatever, but this is your son you're talking about.
M-43 W-40 2D - 9 and 5
Emotion, yet peace. Ignorance, yet knowledge. Passion, yet serenity. Chaos, yet harmony. Death, yet a new life.