The Girl Next Door --------by Desire http://www.nocturnal-light.net/fanfiction/story/38/The_Girl_Next_Door/all Summary: Loosely based on Sabrina. Buffy Summers has only had eyes for Liam 'Angel' Giles since she was a girl, and it looks as if her dream may come true, that is unless his brother William has a say in it.
This next one isn't exactly what you asked for because he doesn't change his name in this one but the 'Spike' attitude is there. And I think if you haven't read this one you should.
Promised --- by Dorians Kitten http://spikeluver.com/SpuffyRealm/viewstory.php?sid=30937Summary: William knew that she considered him a friend or maybe even a big brother, but she'd promised to marry him once and he had every intention of holding her to it. Just as soon as he worked up the nerve to remind her, that is. Who says you can't find your soul-mate in preschool?