My biggest concern is that if it was a family member that is still in the picture, I would like to be aware of that.
That's of course one of the most terrifying and shameful things for a survivor to talk about. A young boy wants his world to make sense, but what sense is he to make of a world in which he is abused at will, for example, by his father, mother, uncle, or big brother? He will often fear that all this was his own fault, and the catastrophic results of this feeling reverberate on into adulthood.
You are right to feel that this possibility would require special compassion and caring on your part, but if there is anything like that in the picture it will be all the more difficult for him to talk about it.
It's one of the most terrible tragedies of child sexual abuse: the more we need help the less willing and able we seem to be to ask for it.