What appears in the earliest text of Romeo and Juliet is "open et caetera," but editors often substitute "open-arse," which was a slang name for the fruit of the medlar. My guess is that such editors do so as a result of societal prudishness. However, I think it's just as possible that Shakespeare actually did write "open et caetera," which makes the meaning clear, but wittily, rather than grossly.
Medlar and Pop'rin Pear