Leaf's given his own feet a try once (it's true, I've drawn it as a commission) and it's not the same for him as worshipping another's feet, part of it is the taste for sure, but another is about the other person's reaction and despite knowing his licks will cause a response, it's still the unknown of how and when, if the toes flex up or curl into his face, maybe a hesitant pull or a more shove against him, other's feet are more to his tastes than his own. He's fine if others worship their own feet, just he ain't into his own set, though he would still take care of them so that another can comfortably worship his feet.