they married there own siblings,, Zeus and hera,,,,,etc...
Apollo has a twin sister, Artemis, goddess of the hunt.
They didn't care about incest among each other.
Genealogy of gods taught mankind to record their own parents, siblings, and children.
In Greek mythology, Atlas was a Titan and his siblings were Prometheus, Epimetheus, and Menoetius. Together, they were part of a generation of powerful beings who predated the Olympian gods.
The Titans,consisting of Rhea,Zues's Mother and Kronos,Zues's Father and his siblings and family.
By 'the big three' I think you mean the sons of Kronos and Rhea. They are Hades, Poseidon, and Zeus. Their siblings are Hestia, Demeter, and Hera.
Poseidon and Hephaestus were both Greek gods, but they didn't have a close relationship like siblings or allies. Poseidon was the god of the sea while Hephaestus was the god of fire, blacksmiths, and craftsmen. They may have interacted in stories involving other gods, but there is no significant bond between them.
Zeus and hades
In Greek mythology, the primary siblings among the Olympian gods are Zeus, Hera, Poseidon, Demeter, Hestia, and Hades. Zeus is the king of the gods, while Hera is his wife and goddess of marriage. Poseidon rules the sea, Hades governs the underworld, Demeter is the goddess of agriculture, and Hestia is the goddess of the hearth. These siblings are all children of the Titans Cronus and Rhea.
All of them believed in it; they were immortal.
Pluto's brother's name is Zeus. Zeus is the king of the gods in Greek mythology and is one of Pluto's siblings.