A male housing of a connector assembly has moving plate (30) with a pair of resilient locking pieces (34) that can be curved resiliently and deformed to incline a projecting direction of the resilient locking pieces (34). A female housing (50) causes the moving plate (30) to interfere with initial position holding projections (18) and pulls the moving plate (30) back to an initial position by locking with locking portions (55) to the resilient locking pieces (34). The initial position holding projections (18) are paired and spaced apart in the same direction as a separating direction of the resilient locking pieces (34) and are arranged at positions different from the resilient locking pieces (34) in the separating direction of the resilient locking pieces (34).