I Does it make it any better for them/him not to talk about it?
He/they can't talk about it till they are good and ready. i would suggest however they "take a look on the internet" first.
I'm assuming they/he has disclosed to you. This does not give you license to bring things up unless he has allowed it before. But if you officially "know why" he has these explosions, you might tell him there are some "mighty good resources on the internet you might want to check out."
What may be bothering them is the myths of CSA survivors. I'd point them no-where except "gee Tim, you might find it interesting that the myths have been dispelled."
If you can take the keyboard, Google: "myths of male sex abuse children" The second or third hit brings you right to the myths section.
But I would not do a lot of "directing" or leading. Its a major scare-off.