Egg yolk.

I'm thinking of checking on my 3rd-year middle school son. The reason I make fried eggs perfectly is because he only peels off the whites and eats them. He also leaves or eats the remaining yolk. I don't force him to eat, but it has become a strange eating habit. When making egg rice, he insists on undercooking the yolk to make it taste better, so he undercooks it completely. He only doesn't eat the yolk of the fried egg. Isn't that odd!