A character gets duplicated into multiple identical bodies, usually through sci‑fi tech, magic, or some shady lab setup. The sex often turns into a swarm of lookalikes sharing one partner or a selfcest situation where someone fucks their own copy, with lots of mirrored poses and repeating faces in the panels. It commonly escalates into group sex, rapid-fire creampies, and the gag of one exhausted body while fresh duplicates keep going.