From this blog:
Here are some DOs and DON’Ts I’ve learned through my own experiences and in conversations with others, for you to better honor your relationship to LGBT friends and loved ones when someone comes out to you.
• Recognize this as a sacred moment – thank them for their trust and courage, and realize your reaction will likely stick with them in this vulnerable space you’ve been invited into (though your long-term engagement is more important than your short-term response). Cherish the intimacy and honesty they’ve extended.
• Take time to listen.
• Take language cues from them, not the other way around (e.g., don’t say ‘gay’ if they say ‘same-sex attraction’, and vice-versa)
• Realize that in many cases, this is not an invitation to a hours long discussion on human sexuality. It’s okay to ask questions, but try to let the other person set the tone – they may not want to process or reflect with you.
• Validate their experience as legitimate to them, regardless of whether you understand or believe the same things. It’s ok to just say, ‘Thank you for trusting me with this. I really value your friendship, and I don’t want treat you any differently.’ Then, of course – DON’T treat them differently!
• Don’t assume to know how they feel or what they believe
• Don’t turn the conversation into a theological discussion, unless they initiate that conversation. This isn’t about what you believe – it’s about sharing your life and relationship. If they want to know your beliefs, they’ll ask.
• When you’re unclear about something, simply say :: ‘Tell me more.’ Don’t take a challenging or antagonistic tone just because your experiences reflect different conclusions than their own.
• Many well-intentioned heterosexual folks see gay people as textbooks on homosexuality and gay culture – but it’s not their job to teach you. They may indeed be willing to walk with you and inform you – especially if it’s a close friend – but you shouldn’t enter the relationship with that expectation.