The invention relates to a device for controlling a liquid discharge from a toy gun, comprising: a chamber adapted to receive a pressurized liquid, the chamber comprising at least a first sub-chamber and a second sub-chamber, an outlet arranged at the chamber to enable a discharge of at least some of the pressurized liquid received in the chamber; a movable member movably arranged in the chamber; wherein the movable member is movable from a first position to a second position in response to a drop in liquid pressure in the first sub-chamber when compared to a liquid pressure in the second sub-chamber, wherein, at the first position, the movable member is arranged to close the outlet to thereby prevent liquid discharging from the chamber, and, at the second position, the movable member is arranged to open the outlet to thereby allow some of the pressurized liquid to discharge from the chamber. The invention also relates to a toy gun for discharging a liquid, comprising: a tank adapted to store a liquid; a nozzle adapted to discharge under pressure at least some of the liquid stored in the tank; and a conduit adapted to fluidly connect the above described device with the tank.