Challenge:
SpoilerObvious one is murdering the moon. Less obvious one is the large number of people that would probably die as a side effect of the moon exploding. Even less obvious one is if our narrator is actually unreliable/delusional and killed his girlfriend.

Lyrics

Verse

I was out one Sunday, walking on the beach
my baby there beside me, though our stay much too brief
Strolling in the surf, when she slipped on a rock
The current took her under, I froze up with shock

I tried to pull her free
The waves, too power-filled
she surfaced once, then was gone
and it was just an hour till

the police took me to the station
Asked the state of our relations
Put on cuffs in slow-motion
Said I killed her, a big commotion

I exclaimed with much emotion
It wasn't me, it was the ocean!

[break]

V2

As I sat in prison, I hatched a scratchy plan
I scrawled my revenge, on the back of my bedpan

I was a model inmate, read all the physics books
bribed all the guards, the gangs and the cooks
Working in the kitchen, I staged my escape
I baked myself into a giant birthday cake

[Break]

I know this part sounds strange, but it was a prisoner-operated pastry shop called Taste of Redemption, sending birthday cakes to impoverished youth, they're really doing a good thing there, but I digress.

V3

Said happy birthday Thomas,
Then I bade him farewell
I tracked cake out his doorway
I was feelin' swell

I built my evil lab'ratory
Set my sights upon the sky
The tides they took my baby
So now moon you gotta die

CH

I blew up the moon
I blew up the moon
It popped like a balloon
I blew up the moon

I blew up the moon
I blew up the moon
Then I wrote this tune
Oh yes I blew up the moon

[musical break]

Murderd the moon
Got cake in my shoe
It’s all over the room
Someone should get a broom

CH

It blew up like a flower
watched the show for an hour
Flower Moon here in May
In June got blown away

I blew up the moon
I blew up the moon
It popped like a balloon
Oh yes I blew up the moon

I blew up the moon
I blew up the moon
Then I sat down, wrote this tune
Oh I blew up the moon