Facing up to reality
I’m a pretty relaxed parent, and I know that kids are curious creatures who often make comments that adults would find embarrassing. The best thing to do is answer their questions factually and kindly. It’s also important to remember that other people are dealing with their own difficulties.
So, I do think that it was a bit much for this dad to expect the narrator to cover up his own face, just because he wasn’t willing to explain to his child what was going on. I can’t imagine how awkward the rest of the flight must have been for him.