I would want to know.
I have flashbacks and partial memories at times, and some weird creepy feelings about things, similar to your feelings about why your son should not wear boxer shorts.
That's why i want to know everything, and EMDR helps me have more memories and flashbacks and gets more memories to come back so I can work on healing.
Yes, it hurts, but in the end, it's going to be for the best because I will be more healed, I hope. I am more healed now that I was 2 years ago.
I have memories of my father walking around the house in see through white cotton thin underwear. Our house was very old and the shower was in the basement and he would not let me cover myself with anything more than a towel, and I had to walk past him in the living room to get to my bedroom, wrapped in that towel after my shower. There were no locks on the doors. I should have killed him. He is dead now, but he will never be dead enough.
Your brain shuts off memories that are too terrible to remember so you can survive daily living when you are a child. You have to rely on those people to live. I think it's related to 'learned helplessness.' You just stop fighting back.
When I turned about 14 I stopped being passive and threatened to kill him with a cast iron skillet, and he reduced the abuse to verbal and the occasional hitting.
The younger memories, I assume, are going to be more than one-time events. When people molest children, they are caregivers, and they do it on a regular basis. If your instincts are about boxer shorts, you are probably right.