Quick coupling for fluid conduits

The connector i.e. plug-in quick connector (1), has a connecting piece (2) fixed into a receiving opening (3) of counterpart (4) and lockingly engaged with the counterpart over a detent device e.g. resilient latching arm (5). A supporting device (7) supports the piece on the counterpart such that supporting device is secured against tilting, where the supporting device is moved relative to the piece. The supporting device is held on the piece such that the supporting device is movable along an axis of piece, where the supporting device comprises a supporting portion (70) e.g. flexible tongue. An independent claim is also included for a connection device comprising a quick connector.