The Merc with a Mouth is bouncing off the walls with joy because he's getting married today! Hush now, Deadpool. The lucky bride/groom/sword doesn't know yet, so calm down.
-via Fashionably Geek
UDPATE 8/21/14: In the comments, LuvMyStuffies correctly points out that this dress is actually the one that Kaylee wore in the Firefly episode "Shindig."