In Hesiod's Pandora story, Prometheus warned his brother not to accept Zeus's gift.
Prometheus was a Titan famous for stealing fire from the gods and giving it to humanity. Zeus responded by arranging Pandora's creation and sending her to Prometheus's brother, Epimetheus. Prometheus understood Zeus's hostility and advised Epimetheus to reject gifts from Olympus.
Epimetheus ignored the warning and accepted Pandora. The story thus contrasts the brothers' names and personalities: Prometheus is often interpreted as connected with forethought, while Epimetheus is associated with thinking afterward. Their opposing responses drive the myth's central event.
Prometheus is not Pandora's husband. That role belongs to Epimetheus. This is one of the most frequent errors in short retellings, especially because Prometheus is the more famous Titan and is closely linked to the story through the theft of fire.