A wedding is a once-in-a-lifetime event for people who don't suck at relationships, and considering the long-term commitment you're making to both another person and your credit card balance, it's only natural you want everything to go as smoothly as possible.
Sadly, it's almost impossible for a couple to get through their wedding day without suffering a single hitch, such as one of the two people not showing up (or perhaps something less serious and slightly more ironic, like rain).
More often than not, it's the guests who are the problem because when you combine people's predisposition to do stupid things with an open bar, it's only a matter of time before someone does something that makes everyone else roll their eyes.
These are just a few of the people you don't want at your wedding. Be sure to act accordingly.