Corvo turned to go when Tramp stripped off. He wasn't a prude, having lived in a barracks-style situation during his training and then having been imprisoned for months, and he somehow wasn't surprised that Tramp didn't possess much in the way of body shyness. The man was a dog after all.
But he turned back at Tramp's rather amazed reaction and grinned. The other man looked like he'd discovered manna from heaven.
"This why humans like bathing so much," he said with a laugh. "Think of being outside on a cold miserable day and then coming in and jumping into a nice hot shower or sinking into a big tub of hot water."