All Human fic where Giles is Spikes dad and Spike is dating Buffy

I don't remember much about this fic other than I liked it and that Spike is Giles son. Spike is dating Buffy and she's dragging her heels about getting married so he has his doctor switch her birth control pills for a fakes. He's following his dad's example, as Giles got Spikes' mother to marry him this way. Only Buffy finds out... Any ideas?

I think this is the one you want:

Make Her Own Way--- by spufette

http://spikeluver.com/SpuffyRealm/viewstory.php?sid=7410&warning=NC-17

Summary: Buffy Summers is the mistress of Spike Giles, the most powerful man in Sunnydale. She loves him, he loves her and all, but he is also a control freak. Buffy wants to make in on her own, somewhat, but Spike is not willing to let her even try. His life, Spike's, concerns Buffy, even though this is a different tale of mistress and lovers. Buffy is trying to be independent, Spike is so not married. It's Buffy that is the one who does not want to marry!

This is the fic! Thanks so much. Sorry for taking so long to respond.