More long-term winteragent/Bucky being John's son's stepdad thoughts:
Starting around, oh idk, middle school probably, the kid gets in the habit of sitting down next to Bucky and going, "so, we had a history lesson today in school."
Bucky freezes, before just sighing. "Which era?"
WWII stuff isn't so bad. Questions about Steve, the war in a general enough sense that he can talk about. Some questions are touchy enough to warrant a "no comment."
The later eras warrant that a lot more. Any assassination attempt or unsolved case: "was that you?" "No comment."
Whenever the kid tries to ask about the torture/brainwashing, Bucky just answers, "we can talk about it when you're older."
At some point in high school he's like "I'm almost an adult, how much older do I have to be??"
And Bucky is like, "well, let's see, I finally came to terms and healed from it when I was about 100. So how about then?"
The kid just rolls his eyes in response.
There're probably times where John jumps in, has to tell his son to cool it with the questions and respect when his stepdad doesn't want to talk about these things.
Maybe at some point when his son is old enough he starts putting together that a lot of his stepdad's quirks are actually products of and coping mechanisms for his past. He gets old enough to understand that the random things Bucky gets sensitive about are triggers, and he should be more mindful about it. At some point he grows up from a curious kid to an understanding adult who realizes that there are some things Bucky just may never want to tell him about and that's okay.
