An assembly comprising a cable-side connector and a partner connector configured to be connected to the cable-side connector, the cable-side connector comprising: an outer conductor shell; and an insulator housed in the outer conductor shell with the insulator holding multiple terminals, wherein the outer conductor shell includes an inclined portion having elasticity in such an inclined shape that a side wall is raised, a lock protrusion as an engagement portion configured to be engaged with a lock hole as a partner engagement portion of the partner connector, and a fitting portion to be fitted in a fitting recessed portion of the partner connector, the inclined portion is provided at the side wall of the outer conductor shell which is configured to contact part of the fitting recessed portion of the partner connector, and when the inclined portion contacts the part of the fitting recessed portion, the lock protrusion closely contacts the lock hole with no clearance, characterized in that the inclined portion is configured to contact an edge portion of the fitting recessed portion of the partner connector, and when the inclined portion contacts the edge portion of the fitting recessed portion, a tip end side of an inclined surface of the inclined portion is configured to contact an outwardly inclined edge portion extending from the edge portion of the fitting recessed portion such that the inclined edge portion is pressed by elastic force of the inclined portion so that the cable-side connector is pushed back and an outer wall of the lock protrusion is pressed against an inner wall of the lock hole. an outer conductor shell; and an insulator housed in the outer conductor shell with the insulator holding multiple terminals, wherein the outer conductor shell includes an inclined portion having elasticity in such an inclined shape that a side wall is raised, a lock protrusion as an engagement portion configured to be engaged with a lock hole as a partner engagement portion of the partner connector, and a fitting portion to be fitted in a fitting recessed portion of the partner connector, an inclined portion having elasticity in such an inclined shape that a side wall is raised, a lock protrusion as an engagement portion configured to be engaged with a lock hole as a partner engagement portion of the partner connector, and a fitting portion to be fitted in a fitting recessed portion of the partner connector, the inclined portion is provided at the side wall of the outer conductor shell which is configured to contact part of the fitting recessed portion of the partner connector, and when the inclined portion contacts the part of the fitting recessed portion, the lock protrusion closely contacts the lock hole with no clearance, characterized in that the inclined portion is configured to contact an edge portion of the fitting recessed portion of the partner connector, and when the inclined portion contacts the edge portion of the fitting recessed portion, a tip end side of an inclined surface of the inclined portion is configured to contact an outwardly inclined edge portion extending from the edge portion of the fitting recessed portion such that the inclined edge portion is pressed by elastic force of the inclined portion so that the cable-side connector is pushed back and an outer wall of the lock protrusion is pressed against an inner wall of the lock hole.