This song is titled 'Hate Story', based upon 'Love Story' By Taylor Swift. It is a song I think Lily would have sung, or at least have had go through her mind, before she realized that she did love James.
I close my eyes
And the flashback starts
I'm sitting there
In a compartment on the train to school
See the lights,
See the students the teachers
I see you make your way through the crowd
We both say hello
Little did I know
That you were arrogant you thought you were better
And my friends said stay away from that idiot
And you were mean to Severus
I was hoping that you’d just go, and I said
James I hate you please leave me alone
You keep asking, and I keep saying no
You're not the prince and I'm not the princess
It's a hate story James just quit it
So I sneak out to the library to hide from you
I keep quiet cause I really hate you
So I try and
Escape this school for a little while
'Cause were arrogant you thought you were better
And my friends said stay away from that idiot
And you were mean to Severus
I was hoping that you’d just go, and I said
James I hate you please leave me alone
You keep asking, and I keep saying no
You're not the prince and I'm not the princess
It's a hate story James just quit it
James I reject you, then you try to tell me how you feel
You are difficult, and sadly real
You should be afraid
I’ll jinx you if you bug me
It's a hate story James just quit it, oh,
I got tired of waiting
Wondering if you would ever just go away
I hoped your love was fading
Then you tracked me to the outskirts of town I said
James you love me, but I want to be alone
I keep hiding from you but always tend to come
I wish you were in my head, You make it hard to think
You leaned down from your broom and smiling
You said
Go out with me Lillian I don’t want you to be alone
I love you and that's almost all I really know
I talked to my friends please think about it
It's a love story Lily just say yes
Oh, oh, oh
Oh, oh, oh, oh
Cause we were both young when I first saw you