A stick in the mud.
More Traditional Proverbs:
One who looks for a friend without faults will have none.Traditional
Speak and the man shall be shown.
Traditional
It is always term-Time in the Court of Conscience
Traditional
Friends are flowers in life's garden.
Traditional
An honest man is hurt by praise unjustly bestowed
Traditional
When April blows his horn, 'Tis good for both hay and corn.
Traditional