Wife had an important conversation with her adult son. One of those, “I didn’t tell you this before because you were a kid; you are clearly an adult now. There are things in family history that you should know.”

Went well. I wasn’t there because I’m not blood and wasn’t around for the relevant events. Besides, they need time without step-dad.

Spent entire day worried for them and hoping it would go well. Sounds like it did. Good outcome for a kind of draining, high-stakes day.