"Forbidden Legend: Sex and Chopsticks goes under the Chinese name Xin Jin Ping Mei, and is apparently based on the 17th Century novel The Plum in the Golden Vase."
There is his legal defence: - ahem - cultural research. A bit like in the West getting caught reading "the story of oh" or anything by The Marquis of Sade. I would recommend he studies the South Park episode where Cartman contrives a pre-emptive explanation for why (he thinks) his friends are about to see a picture of him with the penis of a sleepover friend in his mouth. His culture vulture "I'm doing mad cultural projects" explanatory tone as he preemptively shows the picture at his class "show and tell" is a wonder to behold and gets him 70% of the way to a full explanation. Hey, the remaining 30% hangs in the air like an unexplained pregnant hippo, but, that's still *almost* better than having no explanation at all, and at the end if the day, there's no escaping the truth, but at least he can distract from it a little. Perhaps. Maybe.
OK he's screwed.