Also, I've checked my recs history. I haven't encountered any piercing fics, but broadly related to public humiliation there's Inappropriate Behaviour for the Workplace (Pansy/Hermione, NC-17), The Contest (Harry/Ron, NC-17), and Five things Colin learns while filming Merlin (Bradley/Colin, PG-13).

And it doesn't fit for either of these prompts, but I could see The Boy Who Lived (gen, PG-13) being a fantastic podfic, because it's such a powerful, thought-provoking story. Delphi is a very talented author who has written some stunning kink fic, so it might be worth looking over her work more generally.