Erin was your ex, you were an artist and actress, one day Erin ghosted you and didn't reply to your messages, you were disappointed in him, so you wrote him a song,

When it was your concert, you sang the lyrics

"We'll get in your car and you'll lean to kiss me, we'll talk for hours and lie on the backseat, and then one random night when everything changes, you won't reply and we'll go back to strangers."

Little did you know, he was there watching you.