Here are a few for you to check out:
Iced Heat by missus_grace
Summary: It's the summer after Season 4 and Buffy runs into Spike one hot evening.
http://spikeluver.com/SpuffyRealm/viewstory.php?sid=21617Just a Summer Romance by Slaymesoftly
Summary: The sequel to "Are We Friends?", this picks up immediately after Buffy and Spike's night together. Can they remain friends now? Will it turn into something more? How will the Scoobies and Angel respond if it does? What about Riley? All questions to be answered....
http://spikeluver.com/SpuffyRealm/viewstory.php?sid=24993The prequel to this is
Are We Friends?Summary: Buffy is alone for the summer, and she finds a surprising new friend and companion to help her stay amused. Feelings develop between Sunnydales two super blonds and life gets complicated...
http://spikeluver.com/SpuffyRealm/viewstory.php?sid=24981Cheating on Riley by tahmoe
Summary: What if Buffy gave into the dance with Spike in the episode Fool For Love?
http://spikeluver.com/SpuffyRealm/viewstory.php?sid=4324Could Be You by Abby
Summary: You know you wanna dance. Spike knew it, the fans knew it, and this time, Buffy knew it, too. Begins in the alley scene outside the Bronze during Fool for Love and moves swiftly off-canon.
http://spikeluver.com/SpuffyRealm/viewstory.php?sid=35656**This one is a WIP, but was recently updated last month. Just so you know!**Also, if you do a general search for Fool For Love, there are a few others centered around this episode that fit your criteria.