Teaching kids about LGBT

I'm in a mom's group on Facebook and one lady said that her son has been asking questions about one of his friends that has two mommies and she is devastated and doesn't know what to tell him... how would you handle this? I am married to a woman and we have a baby on the way, so I see it as no big deal and if the kid is asking questions just answer them honestly. I would think saying something along the lines of "some kids have a mommy and daddy and some have two mommies or two daddies because they love one another just like anyone else" would be sufficient and most kids would accept that answer. If you don't agree with the "gay" thing maybe add "we don't have to agree with it, but it's not going away and we all try to get along" or something like that. I just can't see why anyone would have such a hard time answering questions about it, how would you handle it?