If your friend does choose to open up, make sure you're not questioning or refuting their feelings. Instead, "use words that validate the hurt," Mai and Whitlock said. They recommended phrases like, "This is a hard issue to talk about. I appreciate you trusting me with your anger and sadness," "I hear you're upset and I get it," or "I'm sorry you had to go through that."
By the same token, don't tell them what you think they should be feeling, either, Lee said. (For example, saying something like "I thought you'd be more upset," "Why are you so mad?", or "Why aren't you more mad?") Again, your ideas and emotions are not the focus here. Leave your expectations at the door and remember that whatever they're feeling is valid.