Isn't Google Translate a fantastic thing?
Using it on La ci darem, the Don Giovanni & Zerlina duet this is what it churned out:
Original: "andiam andiam mio bene, a ristorar le pene..."
True (accepted) meaning: "let's go, let's go my dear to heal the pain..."
Google Translate translation: "let us go let us go my own good, to restore his penis..."
It seems that Lorenzo Da Ponte was playing with his audience here, and the double entendre will quite likely have been intentional. His humour was apparently just as vulgar and scatological as Wolfgang's. Time to revisit Cosi, Don Giovanni, and Le Nozze di Figaro to look for more?
And meanwhile, well, let's be happy that Google Translate is so incredibly insightful!