Offending At A Wedding
Show up totally smashed. Be as obnoxious and unruly as possible.
When the priest says his little "If anyone know any reason..." ditty, say, "Look at him! Look at her! These people should not reproduce!" or rattle off every mean, nasty thing the ex ever did to you, including that time when he went to see "Jesus Christ Superstar" with his mother on the night of your anniversary.