SPOILER
Rather than being out to his parents, I think it's much more likely that the parents, particularly his mother, know that he is, as Mrs. Muller describes, "that way". Parents usually know before children themselves know. The boy is described as shy and quiet, and his mother talks about his "nature". All code, I believe for a boy who is gay but doesn't yet know it himself.
Coincidentally, a friend with three boys has a 12-year-old son going through the exact same phenomenon. His mother and father assume that he is gay, but he has described himself as "confused" as to what he is.
"Gif me the cobra jool!"