Author's Note: Lyrics are from One Direction's "One Thing". I do not own Sherlock or One Direction, unfortunately.

I've tried playing it cool

But when I'm looking at you

I can never be brave

Cause you make my heart race

I've never been able to explain my relationship with Sherlock to anyone. They always assume there's more than exists. "We're just friends," I say. "We're not a couple," I say. And then they all always give me that look. That look that says "You've got to be kidding me." I can't tell them what we really are, because I don't know myself. I know he's my best friend, but should my heart race like that every time he looks at me?

Shot me out of the sky

You're my Kryptonite

You keep making me weak

Yeah, frozen and can't breathe

I've never believed in love. It's just a chemical reaction in the brain. Things like that don't last forever. It's entirely improbable. Then again, I never believed I needed any friends until he came along either. He's my only friend. I can't imagine why I'd need any others. He's all I could ever need. Unfortunately, Moriarty figured that out, too. John's my weakness and everyone knows it but him.

Something's gotta give now

Cause I'm dying just to make you see

That I need you here with me now

Cause you've got that one thing

I've never figured out what it is about Sherlock. I never imagined finding a flatmate would turn into finding my soul mate. I lived my entire life straight and now, in my thirties, I've just figured out that you don't fall in love with a gender, you fall in love with a person. I don't know if he'll ever return the feelings. He says I'm his only friend and getting that much sentiment out of Sherlock is enough for me. That could be enough for me for the rest of my days as long as we're together, because I understand Sherlock and he's the only one I'll ever want.

So get out, get out, get out of my head

And fall into my arms instead

I don't, I don't, don't know what it is

But I need that one thing

And you've got that one thing

I feel like screaming. I can't concentrate with him there; I can't concentrate without him there. If he's there then I can't help but look at him. If he's not, then I worry about where he is. If he's on a date, I wonder if he finds the girl more interesting than me. I've never had a problem like this that isn't cured by composing with my violin. My violin has always been able to ground me. Nothing has ever come up that couldn't be cured by playing and composing. Maybe if I could just touch him. One hug? Maybe a kiss? That could cure it. If this is love, why do people like it so much? It's entirely unsettling.

Now I'm climbing the walls

But you don't notice at all

That I'm going out of my mind

All day and all night

Does he even realize what he's doing to me? These little touches that he's never done before. Nothing much, just a touch on the arm or hand when talking to me. He never touched me before. All it's doing is making me want more. I swear he was staring at my lips yesterday as if he wanted to kiss me. I couldn't sleep last night because I kept thinking about his lips against mine and my hands tangled in those gorgeous dark locks of his.

Something's gotta give now

Cause I'm dying just to know your name

And I need you here with me now

Cause you've got that one thing.

I don't know how to do this. I don't even know if he wants me to do this. I just need him. I've never needed anyone, but I need him.

So get out, get out, get out of my head

And fall into my arms instead

I don't, I don't, don't know what it is

But I need that one thing