Finally they asked him to go out on the balcony and play a game, shouting back in at them what he could see.
The parents got down to business while he stood outside.
"I can see the Brown's cat" he shouts " and the Wilson's are watching TV, and the Johnston's are having sex!"
"What????" exclaimed both parents, horrified. "How do you know???"
And he replied:
Spoiler: