A spray gun includes a gun body and valves configured to control flow of material and air through the gun body. A trigger is mounted to the gun body and is disposed relative to the valves such that the trigger actuates the valves in sequence to begin air flow and material flow. A sensor senses when the trigger is in an actuated state and the sensor causes a pump to begin pumping material to the spray gun. Release of the trigger causes the trigger to leave the actuated state. A detent mechanism holes the trigger in a detent state intermediate the actuated state and a resting state. The sensor does not sense the trigger with the trigger in the detent state. The trigger maintains the valves open with the trigger in the detent state.