At first she was taken in by his charms
But, for me, all he did was set off alarms
She's my kid sister, it's not up to me
But, I still give advice that's totally free

I saw him with Sally, your friend from the gym
Their lips were entwined, your future looked grim
Of course, he won't tell you and neither will she
It broke my heart that it had to be me

I summoned the courage to face all your rage
Then, I made sure we're on the same page
We hatched up a plan to pay cheaters back
We both were so eager to go and attack

But, at the last moment, we weren't sure we could
So we just put acid under his hood
The next trip they took was real short and sweet
No longer a couple, revenge is complete

We never told them we'd figured it out
We were determined to reap seeds of doubt

My sister is ready to let go of this
More than anything else, she's still my Sis