I hadn't found search yet... new to the forum as of today.
That thread was very useful. We have always raised our son understanding about homosexuality because I have a lesbian sister, and we are active PFLAG members. We actually opted to talk to him tonight, while our partner is returning with more to move in. The talk went amazingly well. I do believe it is important to explain to children because my parents were swingers and thought we didn't know, and I remember "catching" them accidentally in kisses, or embraces or touches on several occasions and just being confused by it, thinking I did something wrong. Not something I wanted for my kids to go through.
The talk went really well. I am so happy that the kids are being raised in such a loving family environment. Our partner was so happy that we told our son, she really loves him, and she felt it was important for our son not to think something "Bad" was happening if he ever happened to witness a touch or something. She feels so much more comfortable just "being" now.