A container for consumer goods, the container comprising: an outer sleeve comprising an outer sleeve front wall, an outer sleeve back wall, first and second opposed outer sleeve side walls (212, 213), an outer sleeve top wall, and a first open end; and an inner box comprising: a box portion comprising a box portion bottom wall, a box portion front wall, a box portion back wall, and first and second opposed box portion side walls; and a lid portion hingedly attached to the box portion along a hinge line, the lid portion comprising a lid portion top wall, a lid portion front wall, a lid portion back wall, and first and second opposed lid portion side walls, the inner box being disposed within the outer sleeve and configured to be slidable with respect to the outer sleeve between: a first position, in which the interior of the inner box cannot be accessed by a user; and a second position, in which the interior of the inner box can be accessed by a user, wherein sliding of the inner box from the first position to the second position involves at least part of the inner box passing through the outer sleeve opening; wherein the inner box further comprises first and second inner box side flaps (59a, 59b), each inner box side flap being configured to overlie a portion of the outer surface of a respective box portion side wall or lid portion side wall; wherein, when the inner box is in the first position in the outer sleeve, an edge of each inner box side flap is configured to engage with a corresponding engaging element (231a, 231b) on the inner surface of a respective outer sleeve side wall, to form a locking mechanism for preventing the inner box from sliding from the first position to the second position wherein each of the first and second inner box side flaps depends from an edge of the box portion connecting their respective box portion side wall with the box portion bottom wall; or wherein each of the first and second inner box side flaps depends from an edge of the lid portion connecting their respective lid portion side wall with the lid portion top wall. an outer sleeve comprising an outer sleeve front wall, an outer sleeve back wall, first and second opposed outer sleeve side walls (212, 213), an outer sleeve top wall, and a first open end; and an inner box comprising: a box portion comprising a box portion bottom wall, a box portion front wall, a box portion back wall, and first and second opposed box portion side walls; and a lid portion hingedly attached to the box portion along a hinge line, the lid portion comprising a lid portion top wall, a lid portion front wall, a lid portion back wall, and first and second opposed lid portion side walls, the inner box being disposed within the outer sleeve and configured to be slidable with respect to the outer sleeve between: a first position, in which the interior of the inner box cannot be accessed by a user; and a second position, in which the interior of the inner box can be accessed by a user, wherein sliding of the inner box from the first position to the second position involves at least part of the inner box passing through the outer sleeve opening; wherein the inner box further comprises first and second inner box side flaps (59a, 59b), each inner box side flap being configured to overlie a portion of the outer surface of a respective box portion side wall or lid portion side wall; wherein, when the inner box is in the first position in the outer sleeve, an edge of each inner box side flap is configured to engage with a corresponding engaging element (231a, 231b) on the inner surface of a respective outer sleeve side wall, to form a locking mechanism for preventing the inner box from sliding from the first position to the second position wherein each of the first and second inner box side flaps depends from an edge of the box portion connecting their respective box portion side wall with the box portion bottom wall; or wherein each of the first and second inner box side flaps depends from an edge of the lid portion connecting their respective lid portion side wall with the lid portion top wall. a first position, in which the interior of the inner box cannot be accessed by a user; and a second position, in which the interior of the inner box can be accessed by a user, wherein sliding of the inner box from the first position to the second position involves at least part of the inner box passing through the outer sleeve opening; wherein the inner box further comprises first and second inner box side flaps (59a, 59b), each inner box side flap being configured to overlie a portion of the outer surface of a respective box portion side wall or lid portion side wall; wherein, when the inner box is in the first position in the outer sleeve, an edge of each inner box side flap is configured to engage with a corresponding engaging element (231a, 231b) on the inner surface of a respective outer sleeve side wall, to form a locking mechanism for preventing the inner box from sliding from the first position to the second position wherein each of the first and second inner box side flaps depends from an edge of the box portion connecting their respective box portion side wall with the box portion bottom wall; or wherein each of the first and second inner box side flaps depends from an edge of the lid portion connecting their respective lid portion side wall with the lid portion top wall.