One second-year undergraduate, horrified to be asked to translate in class a passage of Juvenal’s sixth satire containing an obscene term, timidly ventured ‘groin’ as an acceptable rendering. ‘No’, roared Ted, ‘call a spade a spade. It’s penis, Mr —, penis.’From Jim O'Donnell:
Ludwig Bieler, on the other hand, teaching vulgar Latin, had a student encounter the word mentula and ask him what it meant and replied "membrum virile" in a mutter.