One Shoe Wonder

Caleb has the neatest magic trick! He is able to make his right shoe disappear! **Notice that in every picture, his right shoe is missing. Why is this the case? I'd like to know too. He is constantly sliding off his right shoe (no matter what type of shoes he wears), and I feel like I'm constantly looking for two matching shoes so we can go out in public! Interestingly enough, he doesn't mind walking around sort of lopsided with one shoe on, but being a paranoid mother (I don't want this to somehow mess up the length of his legs), I'll either keep putting the shoe back on him or just take the other one off.