Several weeks after the fact, I happened upon a New York Times Q&A ("Season's Greetings, with a Wink") with John Waters that contained the following bon mot (among others):
WHAT KIND OF GIFTS DO YOU GIVE?
I always give books. And I always ask for books. I think you should reward people sexually for getting you books. Don’t send a thank-you note, repay them with sexual activity. If the book is rare or by your favorite author or one you didn’t know about, reward them with the most perverted sex act you can think of. Otherwise, you can just make out.
No comment! Cheers, Steve