A connector comprising: a mating housing including a locked section; a housing fitted into or detached from the mating housing; and a fitting detection member assembled to the mating housing and movable between a temporary locked position and a regular locked position when the mating housing and the housing are fitted, wherein: the housing includes a member housing section configured to house the fitting detection member, a lock section locked to or detached from a locked section of the mating housing, and a flexible lock arm having locking release sections each of which is configured to slide along an inclined section of the fitting detection member and to release a locked state of the lock section and the locked section, the fitting detection member includes the locked portion locked to or detached from the lock section of the flexible lock arm, and a flexible arm section provided with a slip-off prevention locking section locked to or detached from a locking protrusion of the member housing section, and when fitting of the mating housing and the housing is released, the flexible arm section is bent and deformed in a direction in which a locking margin between the locking protrusion of the member housing section and the slip-off prevention locking section of the flexible arm section increases. a mating housing including a locked section; a housing fitted into or detached from the mating housing; and a fitting detection member assembled to the mating housing and movable between a temporary locked position and a regular locked position when the mating housing and the housing are fitted, wherein: the housing includes a member housing section configured to house the fitting detection member, a lock section locked to or detached from a locked section of the mating housing, and a flexible lock arm having locking release sections each of which is configured to slide along an inclined section of the fitting detection member and to release a locked state of the lock section and the locked section, the fitting detection member includes the locked portion locked to or detached from the lock section of the flexible lock arm, and a flexible arm section provided with a slip-off prevention locking section locked to or detached from a locking protrusion of the member housing section, and when fitting of the mating housing and the housing is released, the flexible arm section is bent and deformed in a direction in which a locking margin between the locking protrusion of the member housing section and the slip-off prevention locking section of the flexible arm section increases. the housing includes a member housing section configured to house the fitting detection member, a lock section locked to or detached from a locked section of the mating housing, and a flexible lock arm having locking release sections each of which is configured to slide along an inclined section of the fitting detection member and to release a locked state of the lock section and the locked section, the fitting detection member includes the locked portion locked to or detached from the lock section of the flexible lock arm, and a flexible arm section provided with a slip-off prevention locking section locked to or detached from a locking protrusion of the member housing section, and when fitting of the mating housing and the housing is released, the flexible arm section is bent and deformed in a direction in which a locking margin between the locking protrusion of the member housing section and the slip-off prevention locking section of the flexible arm section increases.