It all started when Taylor Swift used one of Justin Bieber’s songs in her YouTube video earlier this year. Justin Bieber responded with the video above back in August.

Justin dedicated his never-heard-before song “Favorite Girl” to Taylor. Who would have known that months later on November 3rd “Favorite Girl” would release to iTunes and get an amazing response from fans.

Justin Tweeted to Taylor yesterday: “@taylorswift13 my song FAVORITE GIRL i sang to u on youtube came out 2day on ITUNES…u like?”

To which Taylor responded: “@justinbieber Guess who KILLED IT on @theellenshow…… (you)”

We’re loving Justin’s new song, what about you?