I tried to search and see if someone had posted a search for this already but had no luck. Maybe I was doing it incorrectly... I apologize if that is the case.
Looking for a fic where BOTH Spike and William are twins who fall in love with Buffy, Spike and William are both Vamps I think... Buffy is being held 'captive' by them and they are trying to prove to her that they love her. They have a threesome and Buffy gets pregnant with Dawn. This is sort of a one/few-shot.
Then in the next part (or sequel, not too sure) of the fic, Dawn is shown as a little girl and they are at the movies when Buffy, William, and Spike run into Angel and Cordy. Angel doesn't know that Dawn is the child of both William and Spike. They go home later and Buffy gets pregnant again and the story ends there... with her saying "did you get me pregnant again?"
Does anyone have a clue about this fic? Its been bugging me for a while. Can't seem to remember the title or the author. HELP PLEASE! | 
