Black Keys' Dan Auerbach -- I Dare You To Talk Crap About My Second Wedding

Black Keys guitarist Dan Auerbach and Jen Goodall said "I do" ... and they made all their reception employees swear "I won't" bad-mouth the bride, the groom or anything about their big day.

Dan and Jen tied the knot Saturday at his home in Nashville, and made everyone working the ceremony sign a confidentiality agreement ... which is not uncommon for a celeb wedding.

However, this contract wasn't about protecting details like the gown designer or the menu -- it was all about blocking trash talk. We're told anyone who does say a nasty word about Dan or Jen will be dragged to court.

Kudos to the newlyweds, and we hear the chicken was delish.