"You could, but that isn't beer. I'd have to have authorities look into it. Watering down the liquor could cause a few problems for your boss." Charlie didn't threaten; he was stating a simple fact as he saw it. He didn't seem to mind the bad singing going on behind him.
"I'm not really an anything sort of guy. Just try to exist in the here and now." He nodded in thanks for the beer. "I came to see how you were doing. Make sure you were doing okay."