Is this creepy as heck? Sure it is! But isn't it fun to creep out your friends by finding out what your doppelganger couple's wedding would look like? Think how you'll impress that cute guy in class by saying "hey I found a couple with our names that got married in 2009 and had this cheesy site." Is this kind of making fun of people's wedding websites? Of course, but that's ok because weddings are just another bat-shaped throwing star in the utility belt of The Patriarchy and should be mocked.
Google (or Bing, if you're that type) two first names in quotes, and BAM! You'll find your bizarro self. A lot of the time, you'll get a defunct wedding website as the first result, or at least on the first page.
One thing - this works best if the first names aren't too uncommon, and there's no celebrity couple with those names - searching for "Tom and Katie" or "Brad and Angelina" isn't going to work. If you don't hit paydirt at first, try swapping the order of the first names.
Here's a few examples with some random names - add your own at the bottom. Happy lurking!