Disclaimer – I do not own the song, which is called Constantly by Emmy the Great, and the title comes from this. I do not own the characters mentioned, or the quote from the Deathly Hallows because I am not JKR. The idea, however, is all mine.

S

The last time that I see you

It is something in the morning

The last time we spoke, you said you wanted nothing more to do with me. But from the moment I saw you, I could never leave you alone.

What I want doesn't matter. It is what I have to do that counts. Hatred and love freeze my heart, but both burn like a furnace. It spits up in my eyes, my voice, my soul.

It's such an insult. I loved you, I loved you more than I've ever, ever loved anyone, more than I ever will love anyone because you ruined love for me. You ruined love for me, you ruined me and now I have to stand in front of a classroom and not want to kill the boy who looks like Potter.

The only thing stopping me is you.

Your eyes, your eyes will never leave me. Instead of looking at me with friendship (love), they look at me with anger.

Your iris is a universe

Its etchings are forever

I can never stop thinking about you, and some days I hate you for that. I am bitter and bruised, unfeeling and unloved.

It is so much harder to look at Potter's boy when his eyes are defiant, hostile, arrogant as the one before him.

You were never arrogant.

Maybe you're watching me from above. Maybe you're furious with me for the way I'm treating him. Maybe I don't care because maybe, just maybe it's your husband's fault.

Husband. All those times you told me you loathed him like I did. All those times you lied to me, because I saw you laughing at his jokes, I saw you laugh that day – my worst day. I was humiliated in front of the school, Potter and Black hung me up and filled my mouth with soap and you laughed. What kind of friend does that?

I called you Mudblood. I relive it all the time. I'm sorry, I said I was sorry and did you care?

You did not.

But I would have stayed your friend if only you'd had accepted my apology. I'd have ignored your laugh and remembered your outburst at Potter, poured over it like it was the oxygen to help me breathe. I would have buried the laugh.

Except I wasn't good enough for you anymore.

Our heartless river flows constantly

The pages will unfold for you and me

You said none of my friends can understand why I even talk to you. Do you think mine did? Do you think it was easy for me to explain to everyone why my best friend was the Mudblood who didn't deserve to be at Hogwarts? Do you know how hard it was for me to lie and lie and protect you from all the people who would have used the same magic on you as on Mary MacDonald?

Do you know how hard it is for me to lie and lie?

I am now the bitter, unfeeling teacher. I do not have friends, only those I am obligated to and those who oblige.

You are now the dead, adored mother. You do not have friends, but you did, and you used to be mine.

I mirror you.

Not your happiness. I take it in my heart and let it stab me, every day, all the time, so I am able to remain impassive.

But I do mirror you.

My Patronus is a doe, the same as yours. All I wanted was to be yours.

You put your life in danger for your son. Now, I risk my own for the same.

And when your eyes, your eyes, no-one else's, look at me with contempt? I mirror it.

I have nothing to give for Potter's son but everything to offer for you.

Hatred and love freeze my heart.

The aching comes and goes

Constantly

Do you know how hard it is for me to love you? Your memory is tainted by Potter's face.

And yet.

I will do what is asked of me. I will play the role I am given, the bruised and the unloved. In many ways, I am the same after you as I was before you. I live in the same house, in the same town, the same county, the same country, the same continent, the same world.

But you are beyond the universe, beyond me, beyond anyone. You will never laugh again, I will never hear your voice. I will never see crimson and emerald, I will never see love.

And now I teach, and I teach, and I say the same things every year. I intimidate, I bully, I have become everything you accused Potter of being. Then again, you married him.

You married him and he got you killed.

So now, now I teach Harry Potter and I see your eyes from Potter's face. It is my job to ensure he survives. I have to coerce and pretend because the ice in my heart will never let me forget:

It was my fault.

I know people reap what they sow, but karma is so viciously cruel.

You were killed and you died Lily Potter but you were born and you lived, Lily Evans.

You are the ice in my heart.

You wanted nothing more to do with me, but from the moment I saw you I could never leave you alone.

Your son, he has your eyes.

And your eyes, they hate me.

I don't want to ache

Constantly

S

Author's note – I heard the song and thought it really fit, so much so that I wrote this in the space of 45 minutes. Hopefully, it comes across as I hoped - I haven't written a fanfic in a while, so I appreciate any reviews! Thanks for reading!