Are there any fics out there in which Buffy is pretending to be a boy, out of necessity or otherwise? Canon, AU or AH doesn't matter.

Doubled and Redoubled by Cas. Available at adultfanfiction dot net. AH. They are secret agents (a la James Bond) and Buffy is pretending to be a man at the beginning. One of my favorites!

I found the complete story here.
http://vikingprincess.livejournal.com/202334.html

It is in a better format.