A connector includes a first housing housing a plurality of first terminals, a second housing being fittable to the first housing and housing a plurality of second terminals connectable to the respective first terminals, a short-circuiting terminal housed in the first housing and having contact pieces contacting the respective first terminals which are adjacent to each other, and a release portion provided on the second housing and displacing the contact pieces to release contact between the first terminals and the contact pieces. The second housing is deflectably provided with a lock arm on an outer peripheral surface of the second housing, the lock arm holding a state in which the first housing and the second housing are fit together. The release portion is arranged on the outer peripheral surface of the second housing forward of the lock arm in a fitting direction of the first housing and the second housing.