Liquid dispensing nozzle , characterised in that it comprises: - a liquid dispensing opening , - a removable cap intended to cover the opening when it is mounted on the nozzle , the cap comprising an outer casing and an inner casing that are coaxial, the outer casing and the inner casing each have a sealing surface, the casings are mounted so as to be able to move relative to each other in an axial direction (A) of the nozzle between: . a configuration prior to first use, referred to as the storage configuration, in which the sealing surfaces are in hermetic contact with each other; . an unscrewing configuration of the cap when a pressing force applied to the cap is greater than a predetermined threshold, in which a rotation in a first direction of the outer casing drives by friction a rotation of the inner casing in the same first direction , so as to be able to unscrew the cap ; . a safety configuration when a pressing force applied to the cap is weaker than the predetermined threshold or when no force is applied to the cap , in which the outer casing is configured to freewheel relative to the inner casing in the first direction , the safety configuration further corresponding to a configuration in which the respective sealing surfaces of the outer casing and the inner casing are separated from each other so as to allow air to pass between them. - a liquid dispensing opening , - a removable cap intended to cover the opening when it is mounted on the nozzle , the cap comprising an outer casing and an inner casing that are coaxial, the outer casing and the inner casing each have a sealing surface, the casings are mounted so as to be able to move relative to each other in an axial direction (A) of the nozzle between: . a configuration prior to first use, referred to as the storage configuration, in which the sealing surfaces are in hermetic contact with each other; . an unscrewing configuration of the cap when a pressing force applied to the cap is greater than a predetermined threshold, in which a rotation in a first direction of the outer casing drives by friction a rotation of the inner casing in the same first direction , so as to be able to unscrew the cap ; . a safety configuration when a pressing force applied to the cap is weaker than the predetermined threshold or when no force is applied to the cap , in which the outer casing is configured to freewheel relative to the inner casing in the first direction , the safety configuration further corresponding to a configuration in which the respective sealing surfaces of the outer casing and the inner casing are separated from each other so as to allow air to pass between them. . a configuration prior to first use, referred to as the storage configuration, in which the sealing surfaces are in hermetic contact with each other; . an unscrewing configuration of the cap when a pressing force applied to the cap is greater than a predetermined threshold, in which a rotation in a first direction of the outer casing drives by friction a rotation of the inner casing in the same first direction , so as to be able to unscrew the cap ; . a safety configuration when a pressing force applied to the cap is weaker than the predetermined threshold or when no force is applied to the cap , in which the outer casing is configured to freewheel relative to the inner casing in the first direction , the safety configuration further corresponding to a configuration in which the respective sealing surfaces of the outer casing and the inner casing are separated from each other so as to allow air to pass between them. <EOS>