I am often asked by clients or other parent-friends, “My son/daughter asked me “X” the other day. How do I know when it’s right to talk to my kids about [sensitive topics]? And, what should I say?”
This is a common concern for any parent, or, frankly, any adult with children or teens in their lives who they are close with. Here are a few things to think about, in order to find your right response:

When they ask, they are ready.
Sounds simple. And it is…somewhat. If a child or teenager has had the wherewithal to think about a particular matter, have a concern or question arise about that matter, and they have the courage to come out and ask about it, that tells me that they have readiness to get some answers.
Acknowledge your relationship.
It also tells me that there is some level of close relationship between you and that child, which provides enough comfort for him or her to be able to come to you. That is worth acknowledging, at the very least to yourself, that something you’ve done or some way you have been has allowed for this openness.
They want the truth.
Given that they are ready and you have the basis of the relationship you seem to have, respond with honesty. No matter how old we are, we want the truth. This honours your relationship, while honouring each of you. Honesty also provides added confidence for that young person to know that they can come to you again in the future and trust they’ll get the truth. In addition, this confidence transcends your relationship and can contribute to that young person’s personal strength in life, as well as their relationships going forward.
You get to choose what you say or not.
While you want to be honest, you also are the adult and want to bring discretion to what you share or what you don’t share. You don’t need to give unnecessary details. And, you also don’t need to share any information that could make another person look bad.
Make it safe for them to emote and react.
Depending on the topic at hand, the child may react with some emotion. They might be sad and they might cry. They might be upset or angry, and either withdraw or stomp away or let you have a piece of their mind. They may be calm, silent, or say little. Every person (including you and me) has a way of processing new information and reacting physically or emotionally. The key here is that whatever the reaction, it usually has a particular ‘life span’. In other words, it passes. If you and I let them express safely, usually it comes up, gets out, and clears away. If you and I react to their reaction, we add ‘weight’ to the emotion, keeping it around longer than it typically needs to be.
I encourage you to consider these things and incorporate them into your own value system as you see appropriate. I wish you the best with your commitments for peaceful and loving relationships.