coupling device is provided having a male tubular end fitting ; a connection mechanism to be mounted around the male end fitting by being coupled to a female end fitting and including a coupling end to be housed in a groove of the female end fitting ; and a locking member for locking this connection mechanism that is to be mounted around the male end fitting in order reversibly to bring the coupling end into a locked position in the groove . the connection mechanism includes a radially internal bearing zone to be mounted against the male end fitting and ending in the coupling end , which includes tabs that are elastically deformable in the radial direction extending the bearing zone , each tab being able to be jammed in the locking position by flexing against the groove and against one of the guide and locking - aid ramps of the male end fitting .