I encourage students to use the fingering in their music. And of course there are times when they find a different fingering that is more comfortable for their hand. I praise them up and down for "finding their own way" and write their fingering in the music. This is all well and good when they've come up with a decent fingering, but I have one student who is quite a character. He comes up with the most unorthodox fingering you can imagine. When I try to explain why his fingering isn't ideal, he gets pouty and insists that this "works for him." I'm not sure if I should let this slide or be militant about him doing a more "correct" fingering. Thoughts?