I really want to them see them pretend they are girlfriend and boyfriend or wife and husband for some reason. I haven't read a single pretend to be married fic and would love some of these. I do not read and all human, would prefer if Buffy was the slayer and Spike the vampire. Anything else doesn't matter. Please warn me if it has angst or if WIP.

I can't remember how much of a part pretending to date took in this but it was in it...
City of Angels by bittenandstaked
Buffy and Spike are living together after Dawn convinced Buffy to let him stay in their moms room. Buffy realises that Spike isn't such a bad guy once you get to know him, so long as he doesn't corrupt her sister too much.

In Jealousy's Wake by sabershadowkat

Hi,
My favourite is Willamina by maryperk

Summary:

Angel asks Buffy to Los Angeles to meet his new girlfriend Kate. See what happens when Spike helps Buffy with a little revenge. Written for 10yearsofbtvs LJ. Set in a slightly AU season 4

http://www.sinful-dreams.com/wicked/temptation/viewstory.php?sid=61

This one fits the bill
Green Card by RipeWickedPlum
When Spike's threatened by the INS, Buffy steps in to help our fave blond vamp out.
http://dark-solace.org/elysian/viewstory.php?sid=1550

In my The Blindest of Dates Spike and Buffy pretend to be on a date. A sequel is in the works.

In To Save a Lady they are sent back in time to London in William's day and they have to pretend to be married for several weeks.

In If That's What It Takes, they are sent to another dimension in which they have to pretend to be the married Spike and Buffy who live there.