It's almost as though the writers got orders to stretch out what should have been a two episode set into four and having Clark actually use his brain would have forced them to actually think about the story line with REAL complications.
I think the writers were trying to put it off because they wanted their marriage to coincide with the marriage of LL & CK in the comic books, which it did later in Season 4.
Although its possible they wrote this horrible story arch beforehand and then realized how close the comic book was to them getting hitched and then decided to write the horrible NK arch so the two weddings could coincide.
