An electrical connector assembly includes a first connector portion with a first housing with a circumferential inner locking shoulder at a first end of the first housing and a second connector portion interconnectable with the first connector portion, having a second housing with a circumferential outer groove arranged coaxially with respect to a connector axis. A radially deformable locking ring is arranged in the circumferential groove of the second connector portion. The locking ring includes a circumferential outer locking shoulder, behind which the inner locking shoulder of the first connector portion is locked in a connected state of the first and the second connector portion and an unlocking surface that is circumferentially accessible from the outer vicinity in the connected state.