A connector assembly comprising: a first connector; and a second connector, wherein the first connector and the second connector are suitable for being fitted and electrically connected together, the first connector includes: a first housing that houses a first connection terminal; and a protruding portion that protrudes from the first housing toward the second connector along a connector fitting direction, the second connector includes: a second housing that houses a second connection terminal and has a front surface opening to which the first connector is fitted; a cover including a cover portion that covers the front surface opening, a rotation shaft that rotatably supports the cover portion between a position where the cover portion covers the front surface opening and a position where the cover portion does not cover the front surface opening, and an abutted portion with which the protruding portion abuts; characterized in that the second connector includes a slide mechanism (67, 50a1, 40, 28) that slides the rotation shaft toward the first connector in response to pressing the first housing to the second housing, and after the rotation shaft is slid toward the first connector with the slide mechanism (67, 50a1, 40, 28) and the cover portion is seperated from an opening of the front surface opening, the protruding portion presses the abutted portion such that the cover portion is rotated to the position where the cover portion does not cover the front surface opening. a first connector; and a second connector, wherein the first connector and the second connector are suitable for being fitted and electrically connected together, the first connector includes: a first housing that houses a first connection terminal; and a protruding portion that protrudes from the first housing toward the second connector along a connector fitting direction, a first housing that houses a first connection terminal; and a protruding portion that protrudes from the first housing toward the second connector along a connector fitting direction, the second connector includes: a second housing that houses a second connection terminal and has a front surface opening to which the first connector is fitted; a cover including a cover portion that covers the front surface opening, a rotation shaft that rotatably supports the cover portion between a position where the cover portion covers the front surface opening and a position where the cover portion does not cover the front surface opening, and an abutted portion with which the protruding portion abuts; characterized in that a second housing that houses a second connection terminal and has a front surface opening to which the first connector is fitted; a cover including a cover portion that covers the front surface opening, a rotation shaft that rotatably supports the cover portion between a position where the cover portion covers the front surface opening and a position where the cover portion does not cover the front surface opening, and an abutted portion with which the protruding portion abuts; characterized in that the second connector includes a slide mechanism (67, 50a1, 40, 28) that slides the rotation shaft toward the first connector in response to pressing the first housing to the second housing, and after the rotation shaft is slid toward the first connector with the slide mechanism (67, 50a1, 40, 28) and the cover portion is seperated from an opening of the front surface opening, the protruding portion presses the abutted portion such that the cover portion is rotated to the position where the cover portion does not cover the front surface opening.