excellent post, have my upvote. but seriously, my boyfriend is also a stutterer and i find for him it gets worse when he's stressed or sick or nervous, so maybe watch out for that? it's different for every person tho. also, you're absolutely right about not completing his words or sentences, but maybe if you're close enough and you see he's really struggling on a sound, maybe gently suggest it? idk it helps a bit with my guy :) also, my advice would be to just keep doing what you're doing, you're doing great!