Matthew Gray Gubler was 28 in Alvin and the Chipmunks: The Squeakquel when he played the character 'Simon (voice)'.
That was over 14 years ago in 2009.
Today he is 44, and has starred in 32 movies in total, 24 of those since Alvin and the Chipmunks: The Squeakquel was released.
In Alvin and the Chipmunks: The Squeakquel, I think Matthew Gray Gubler looks: