In Greek mythology, Epimetheus became Pandora’s husband after Prometheus warned humans about Zeus.
Epimetheus was Prometheus’s brother and was associated with afterthought, in contrast to Prometheus’s name and reputation for foresight. Prometheus advised him not to accept gifts from Zeus, but Epimetheus accepted Pandora. In the myth’s sequence, Pandora later opened the container kept in their household, releasing troubles into the world.
The marriage is important because it links Pandora’s arrival to the earlier conflict between Zeus and Prometheus. Prometheus had deceived Zeus over sacrificial portions and, in later episodes, stolen fire for humanity. Zeus’s gift of Pandora therefore functions as part of a punishment directed at humans and Prometheus’s family.
Epimetheus is not the same figure as Deucalion, the survivor of the later Greek flood myth. That common mix-up comes from placing several early-humanity stories together.