Buffy in hospital - spike to the doctor "she's my wife"

This scene popped into my head and I know I've read it before but I can't think of the story
Spike comes back from somewhere and Buffy's in hospital for some reason, he says to the doctor "She's my wife / I'm her husband" or something to that effect so that he's allowed to see her [they're not actually married]
I think it's Xander who sort of goes "No you're not" and Spike replies with "were you there ?" and then there's a pretty funny line of Giles considering that they might have actually gotton married at some point.

It's really annoying me - I think it was pre-chip Spike, they had a secret - but short - relationship of some kind and that he did the leaving for her own good bit but I'm not 100% sure of that, I might be mixing

So yeah, I will be eternally grateful if someone can help
thanks
xx

This was a scene in Goldenusagi's "Sideways". You can find the scene in chapter 86.

Link:

Sideways by GoldenUsagi

http://dark-solace.org/elysian/viewstory.php?sid=2123

Summary: Alternate reality. Buffy starts as a normal college girl. But her life is slowly turned upside down beginning with the day she's unexpectedly in danger. Hired by chance to protect her is Spike, a vampire with a reputation for doing business with anyone for enough money. She's less than thrilled, but finds herself drawn to him even as she realizes he's more than he seems. But humans aren't the only ones after her, and when she's called as the Slayer, her whole world changes. Things with Spike, who she's discovered some realities about, are no longer as simple as they seemed. But being sent to the Hellmouth and realizing the high death rate of her calling, Buffy hires Spike as backup with the only thing she has left—Slayer blood.

Thankyou so much
that's exactly the scene I was talking about !
xx