I remembered reading pages of Nantucket limericks in my childhood books. But I Googled (maybe I should have Binged) for it and lo and behold the naughty version is the second result. (A sample line: “If her ear were a **** I could **** it.”)
What surprised/shocked my Mom was that the nun stopped his little poem just at the second line. How in the world did she know the poem?!!! Hmmm? Sister actually sort of chuckled when she told Mom. Mom did not chuckle at all. My older brother certainly didn’t chuckle once that entire weekend.