It wasn't so much that Aziraphale needed sleep. He didn't. But he did like his peace and quiet in the evenings, and he was attempting to enjoy a good book. In this instance, Proust. And listening to Crowley play the bongos at three in the morning leant itself to neither peace nor quiet. Not to mention it could wake up the neighbours, and that would just be horribly disrespectful.
He got up out of the chair in the corner of his room and set down his book, pulling on his dressing gown over his pyjamas and leaving the room to respectfully ask that Crowley please stop with that infernal racket. Of course, that went out of his head when he exited his room to the sight of the naked demon. His eyes took in the cigarette and the alcohol and the strategically placed bongos for a long moment before he could actually speak.
"I..." he said, trailing off, then trying again. "I...really don't know what I should scold you for first."