Jesse McCartney was 27 in Alvin and the Chipmunks: The Road Chip when he played the character 'Theodore (voice)'.
That was over 8 years ago in 2015.
Today he is 37, and has starred in 28 movies in total, 3 of those since Alvin and the Chipmunks: The Road Chip was released.
In Alvin and the Chipmunks: The Road Chip, I think Jesse McCartney looks: