Perhaps Keith could now have a quiet word with Kavanah about his drinking. He has been there so his advice will be valuable first hand experience that Kav could take on board. The two could then be good friends which would continue outside of the house as Keith helps the boy to deal with his problems and becomes a surrogate Father for him, offering him support and going with him to these drink problem group meetings. I think that would be really nice.

which is exactly what bothers Kav. he knows this. and he knows what he should do.

he feels wrongly i may add that Keith is judging him because he knows Keith is sober.
this is Kavs problem not Keiths.