Assembly of two elements mounted to rotate freely one with respect to the other irreversibly

An assembly having an axis of symmetry, said assembly comprising:

• a first element including a snap-fitting bead, said snap-fitting bead extending in a first plane perpendicular to the axis of symmetry and having at least one opening delimited by a first end forming a ramp portion and a second end extending in said first plane;
• and
• a second element including a snap-fitting lip, said snap-fitting lip extending in a second plane perpendicular to the axis of symmetry and having at least one opening delimited by a first end forming a ramp portion and a second end extending in said second plane, said at least one opening of said snap-fitting lip being complementary with said at least one opening of said snap-fitting bead;
• wherein, when said first element and said second element of the assembly are fitted together, said ramp portion of said at least one opening of said snap-fitting bead engages said ramp portion of said complementary at least one opening of said snap-fitting lip in response to a rotation of said first element with respect to said second element so that said snap-fitting lip passes over said snap-fitting bead, thus allowing said second element to be mounted on said first element so that said second element can rotate freely;
• wherein said first element is formed of a container capable of containing at least one liquid or semi-liquid product and wherein said second element includes an operating member;
• wherein said container has a body, one end of said body being surmounted by a dispensing adaptor removably closed by a stopper, wherein said stopper, in a first axial position, is contained inside a cap forming said second element and, in a second axial position, emerges from said cap through an orifice made in a free end of said cap, and wherein rotation of said cap in a first direction with respect to said container causes said stopper to move from said first position into said second position.