Colouring in

My boy sits colouring his picture in.
His tongue and finger movements synchronised,
And concentrating surgically he fills
Each shape with colour. Carefully he tries
So hard to keep within the printed lines.

Despite his careful touch mistakes are made.
Frustrated by the errors he looks round,
Berates his younger sister, then to me
Blames her for jogging him. He moans aloud,
"She made me mess it up and now it's ruined!"