Ian McKellen — Gandalf’s Protecting My Ass

Ian McKellen has magic underwear … and yesterday, he showed off his special tighty-whities during a theater performance in New York City.

Of course, the face protecting Ian”s pooper is Gandalf from “Lord of the Rings” — the character played by Ian in the LOTR movies.

Fun Fact — the undies were actually a gift from “Watch What Happens Live” host Andy Cohen.