This is the type of reaction a child has on their own, without the corruption of politics, parenting, and religion.
I believe that humans are born with open minds. As parents, it is our job to keep those minds open throughout their lives. This kid wasn't traumatized or 'converted' by meeting a gay couple. He was happy to have a new experience... to meet new people. What's so wrong with that?
"so that means you love each other? You're much alike... I'm going to play ping-pong now"