I think one beer alone after people have gone to bed is fine. But, is there something that makes him think he has to hide it? Do you drink? Has he had problems with drinking in the past? Have you said anything like "it's fine if you drink, and you don't need to wait until we go to bed to buy/drink it."
Maybe he likes the evening ritual of going out to by beer and then coming home and having one.
Maybe he likes the evening ritual of going out to by beer and then coming home and having one.
