Happy National
Underwear Day!:
Rihanna Steps Out in a
Bra and Boxers-- Plus
8 Other Celebs Wearing
Underwear as
Outerwear!

To celebrate National Underwear Day (yes, this is a real thing), we've rounded up nine pics of celebs showing off their undergarments in public.

From Lady Gaga to Selena Gomez, is seems everyone in Hollywood is trying out this strange trend! And we're really not sure why...

Anyway, click through the gallery above to see the pics!