A patient interface system for delivering a flow of pressurised air or breathable gas to an entrance of a patient's airway for treating and preventing respiratory disorders comprising: a cushion assembly (150,250,350,450) including a sealing region adapted to sealingly engage with the patient's nose; a positioning and stabilising structure for holding the cushion in sealing position in use via a two-point connection; an air delivery tube for delivering the pressurized air to the cushion assembly, the air delivery tube being rotated when it is elongated; and a decoupling system for decoupling tube drag forces when the air delivery tube for delivering the pressurised air is elongated and is moved relative to the cushion assembly, the decoupling system including: a first decoupling component to decouple rotational movement of the air delivery tube when it is elongated; and a second decoupling component (125,128) to decouple movement of the air delivery tube relative to the cushion assembly; a third decoupling component (158) to decouple movement of the air delivery tube relative to the cushion assembly when the second decoupling component has exceeded a predetermined decoupling range caused by movement of the air delivery tube relative to the cushion assembly; wherein the first decoupling component is a first swivel cuff connection having a first swivel cuff at a first end of the air delivery tube and a second swivel cuff connection having a second swivel cuff at a second end of the air delivery tube; wherein the second decoupling component is a spheroidal joint; wherein the third decoupling component is a decoupling gusset defined in a side wall region of the cushion assembly; and wherein the air delivery tube comprises a helical coil comprised of a plurality of adjacent coils and a web of material coaxial to the helical coil attached to the helical coil. a cushion assembly (150,250,350,450) including a sealing region adapted to sealingly engage with the patient's nose; a positioning and stabilising structure for holding the cushion in sealing position in use via a two-point connection; an air delivery tube for delivering the pressurized air to the cushion assembly, the air delivery tube being rotated when it is elongated; and a decoupling system for decoupling tube drag forces when the air delivery tube for delivering the pressurised air is elongated and is moved relative to the cushion assembly, the decoupling system including: a first decoupling component to decouple rotational movement of the air delivery tube when it is elongated; and a second decoupling component (125,128) to decouple movement of the air delivery tube relative to the cushion assembly; a third decoupling component (158) to decouple movement of the air delivery tube relative to the cushion assembly when the second decoupling component has exceeded a predetermined decoupling range caused by movement of the air delivery tube relative to the cushion assembly; wherein the first decoupling component is a first swivel cuff connection having a first swivel cuff at a first end of the air delivery tube and a second swivel cuff connection having a second swivel cuff at a second end of the air delivery tube; wherein the second decoupling component is a spheroidal joint; wherein the third decoupling component is a decoupling gusset defined in a side wall region of the cushion assembly; and wherein the air delivery tube comprises a helical coil comprised of a plurality of adjacent coils and a web of material coaxial to the helical coil attached to the helical coil. a first decoupling component to decouple rotational movement of the air delivery tube when it is elongated; and a second decoupling component (125,128) to decouple movement of the air delivery tube relative to the cushion assembly; a third decoupling component (158) to decouple movement of the air delivery tube relative to the cushion assembly when the second decoupling component has exceeded a predetermined decoupling range caused by movement of the air delivery tube relative to the cushion assembly; wherein the first decoupling component is a first swivel cuff connection having a first swivel cuff at a first end of the air delivery tube and a second swivel cuff connection having a second swivel cuff at a second end of the air delivery tube; wherein the second decoupling component is a spheroidal joint; wherein the third decoupling component is a decoupling gusset defined in a side wall region of the cushion assembly; and wherein the air delivery tube comprises a helical coil comprised of a plurality of adjacent coils and a web of material coaxial to the helical coil attached to the helical coil.