Disclaimer, the characters are JK's but the song is billy joels. It is a parody of say goodbye to hollywood. Even if you don't know the song please read it cos its kinda sad.

Its how Severus has to go and be a spy and leave her.

Say Goodbye to Hermione


Snape is flying through the sky tonight
Past the stars on a hot new Firebolt
He sees his lover in her quiet little room
It's a dorm down in Gryffindor Tower
Say goodbye to Hogwarts
Say goodbye Severus
Say goodbye to Hogwarts
Say goodbye Severus

Snape has takin' care of things for a while
And his job is incredibly dangerous
They got him actin as a spy for the good
Now his life ain't certain anymore
Say goodbye to Hermione
Say goodbye Severus
Say goodbye to Hermione
Say goodbye Severus

Doing this is a chance that he takes
Cos he wants her to live forever
Whoa
Says a word out of line
And he'll find that he won't live anymore
hes gone forever
Forever

So many faces swim around in his mind
Only will last
The rest will just be now and then
All his life he only once found a lover
I'm afraid it's time to say goodbye for good
Say goodbye to Hermione
Say goodbye Severus
Say goodbye to Hermione
Say goodbye Severus

Doing this is a chance that he takes
Cos he wants her to live forever
Whoa
Says a word out of line
And he'll find that he won't live anymore
hes gone forever
Forever


So now its time, he has said the wrong thing
Now its time
Time for him to leave this life
Hermione sees he's dead and he's cold
She knows now she can't hold him again
Say goodbye to Severus
Say goodbye Hermione