Charivari, aka Disturbing the Newlyweds
There's knowing when and how to toast the happy couple, and most newlyweds would likely agree it's not after-hours at their home on their wedding night.
Charivari -- also called chivaree or shivaree -- likely began during the Middle Ages, and whatever name you happen to call it by, it's all the same bunch of wedding night crashers. Consider this tradition something like caroling during the holiday season, but in this case you're gathering at the home of a newly-married couple on their wedding night with the sole purpose of disturbing their peace (usually with some sort of ruckus such as discordant music, horns or other loud noises) in an effort to be invited inside to toast the happy couple. Ignored? Being ignored by the newlyweds is unacceptable, and over the years, stories not only of noise and hooliganism have been told, but also tales of kidnapping the bride or groom for the night.