Frankly speaking! If a person wants to play guitar he should have an inborn quality of music(Sur). I have seen many guys who just want to play because they have seen people playing it. And it doesn't work al all. I can't explain it, it comes by own. You are lucky that you have a mastered guitarist. All I can say is just feel the music from deep inside and it'll automatically come to the tune.
"Practice does not make perfect unless itís perfect practice and perfection can only be gained at slow speeds, this is a fact"