Hmmm It is true that all men are fifth graders, but it is equally true that all men are also college freshmen at heart too. If I were to make that comment about your tattoo, it would be because I was hoping to see it and a great deal more. But while I might hope for this, I would never announce it over the phone like he did. It seems a bit weird to me too.
I've jokingly referred to lower back tats in the same way. However, I've been involved with two women who had them, and neither was a tramp in any sense of the word.