I have become such a non-believer of anything that comes out of an active addicts mouth, which leads me to say, how can you be certain he is not drinking under his parents roof?
Perhaps mommy and daddy are not as tuned in as they think they are.
So here is an adult grown man running back to the nest for mommy and daddy to protect him because YOU cause him so many problems in life. ( shaking head)
Sorry to say, as long as they continue enable him , nothing is going to change.
Sending you tons of support.