Lyrics:

Rhett:
You looked like my mother
Did when she was 19, not afraid to die
I started planning our future
But you were just 19, still a firefly

Rachael:
You got terrible vision
Shoulda seen I was leavin' when I first appeared
I got bit by the foot lights
I got caught in the headlights, any place but here

Both:
Never say you'll never leave
'Cause you never know till you try
In a jar, fireflies
Only last for one night
Only last for one night

Rachael:
Trains roll like gamblers in slow-mo
Trying to find good luck, where they couldn't find love

Rhett:
Oh yeah, and I, I'm gonna sleep on the train tracks
It's gonna be peaceful, it's gonna get rough

Both:
Never say you'll never leave
'Cause you never know till you try
In a jar, fireflies
Only last for one night
Only last for one night

Both: I must have had a reason for leavin'
Rhett: Not one I could see
Both: I must have had a reason for leavin'
Rhett: Must have been me
Both: Must have been me

Rhett:
You looked like my mother
Did when she was 19, not afraid to die

Rachael:
For the last time I'm not your mother
Hell, I was only nineteen
I'm still a firefly