You shouldn't tell someone their breath smells.
Basil is talking with Jim who has awful breath and keeps backing away from him so Jim asks why he keeps going backwards.
Basil wants to answer Jim's question.
Basil tells Jim it's just a force of habit, and he doesn't like to stay in one spot too long.
Basil tells Jim that his breath is destroying him, and he can't take it anymore, Jim needs to get some mints.
Jim thinks that's a reasonable explanation and happily continues their conversation.
Jim is embarrassed beyond belief and goes away into the bathroom feeling awful about what he's just been told.