[Verse 1]
We run back home
I'm thirteen
Just waiting for the payoff
This house smells like
Old routines
And daddy just got laid off
We traced stencils on the wall
You get bored and I get taller
'Til this room won't fit us
[Chorus]
Follow the grass to the street
The cardboard box we turned into a sled
Dancing in the glow of the TV screen
It'll be us until the end
[Verse 2]
I force you to film me sing
Some random song I made up
Mom is gone for work again
The babysitter feeds us
We're too old for this
We have iPhones now
And I'm pretty sure Barbara stays home alone
Whеn her mom goes out
We'rе too old to have fun the way we used to at thirteen
But we've always been who we'll always be
[Chorus]
Follow the grass to the street
The cardboard box we turned into a sled
Dancing in the glow of the TV screen
It'll be us until the end
The end
“It is until it isn’t” is a rhetorical template that implies something has an unexpected, and typically opposite, meaning or consequence to it–one that is unrevealed at first.
In this case, the action of “tracing stencils on the wall” with her sister is fun until they are punished for it.