So, Xander dad is a homophobic (yeah, that really narrows it down, I know) and Willow and Buffy yell at Xander in the hall at school after he tells them he's gay. His dad hears about it and Xander ends up living on the street. Angelus finds out and tells Giles where to find Xander, so Xander moves in with him.
Here's hoping!
The previous post is here.