"Why?"
"You're naked."
"I am aware of that."
"We do not allow naked people in our museum."
"But you have artwork featuring naked people."
"I realize that. But naked art can't pop a boner. You could. And you're very nice to look at, by the way, much better than the usual nutters who take off all their clothes in here. May I touch your cock?"
"I think I'll leave now."
"Thanks for visiting Vienna's Leopold Museum, sir. And thank goodness this wasn't the United States, where you would've been shot with a taser, arrested, and charged with a sex crime."
