LOL, I've had this one sitting on my "To Read" list for years and just happened to finish reading it today, so that scene is incredibly fresh in my mind. Couldn't ask for better timing.

It's a two part story and Spuffy's marriage in City Hall occurs in the sequel, Universal. Enjoy!
The Ghost in You by BuffyMeetsSpike
Summary: Goes AU during Bargaining. Willow's spell goes awry, leaving Buffy incorporeal, and visible only to Spike. With the Scoobies convinced that Spike has lost it, how can he help Buffy get back where she belongs?
Universal by BuffyMeetsSpike
Summary: This story takes place about a month after The Ghost in You. It is helpful, but not necessary to read that story first. The story takes place in an AU version of Season 6. Spike and Buffy are together, living in her house and caring for Dawn after Buffy was brought back from the dead. Their newfound peace is due to be shattered when they become pawns in a battle between the Powers that Be and a race of demons hungry for power.