Swift had quite possibly the cutest reaction ever to meeting Timberlake for the first time back in 2008, when Ellen DeGeneres (who also made an appearance on the 1989 Tour this year) brought the latter out as a surprise guest on her show. At the time, Swift was promoting her sophomore album, Fearless. See the adorable moment in the video above.
Timberlake even offered up a compliment to his not-so-secret admirer, telling Swift she had a "beautiful voice."
Celebs geeking out meeting other celebs -- we love it! And look how far their friendship has come! See Timberlake hit the stage with Swift for a major moment in the video below.