I feel for you and the anguish you are feeling at the moment. You are endeavouring to work out what is the right thing to do and in the interests of all parties, and that is to be commended.

In any situational analysis there needs to be parameters. In this instance questions such as - what are the motives for disclosure, what is the desired outcome? What does the situation teach me about myself, what is happening internally? Are there any other motives that I am unaware of consciously that are driving this desire? What is the best that could happen? What is the worst that could happen? Has it anything to do with me?

Asking ourselves these sorts of questions can lead to some quite enlightening discoveries sometimes and is well worth the exploration.

The other question would be, is it still a secret? Has he owned what happened and disclosed this as he has matured into his role within the family?

Feel proud of yourself for bringing these thoughts into your conscious mind and analysing them, It shows a good moral compass and great intentions. Awesome