Using children as an excuse for bigotry is probably the oldest most worn-out tropes in all of politics. It's also one of the most offensive.
But I'll give these people the benefit of the doubt. Maybe they really don't know what they'll say when little Johnny comes asking them about the gays. So I'll help them out. Here's an example of what they can say in this delicate situation:
"Well, Johnny, some people are gay, which means they tend to fall in love with people that are the same gender as they are. Your mommy and daddy hate people like that, because we are horrible pathetic excuses for human beings who try to prop up our paltry self-respect by pretending that we are better than other people. One day you will understand that, and then you will move to San Francisco or New York or Lincoln, Nebraska -- pretty much, any place away from your parents will do -- and rent a tiny, squalid apartment with three other disaffected twenty-somethings, and spend your evenings venting your long-held frustrations about the closed-minded ignorant jerks that raised you."