Zeus has cheated on
Zeus fell in love with Io and seduced her. To try to keep Hera from noticing he covered the world with a thick blanket of clouds. This backfired, arousing Hera's suspicions. She came down from Mount Olympus and begain dispersing the clouds.
Suffice it to say that Zeus was constantly involved in extramarital affairs. Throughout the various and sometimes contradictory myths composed by Greek authors, there are at least 20 divine figures with whom he consorted, and about twice as many mortals. Again, the exact number doesn't matter.
Before his marriage to Hera, Zeus consorted with a number of the female Titanes (and his sister Demeter). These liaisons are ordered by Hesiod as follows: (1) Metis; (2) Themis; (3) Eurynome; (4) Demeter; (5) Mnemosyne; (6) Leto.
Despite Zeus' numerous infidelities, Hera didn't once cheat on her husband. Hera was the goddess of marriage and took that responsibility very seriously, which was probably why she was so vengeful to the females whom Zeus pursued.
Zeus finally became enamored of the goddess who was to become his permanent wife — Hera. After courting her unsuccessfully he changed himself into a disheveled cuckoo. When Hera took pity on the bird and held it to her breast, Zeus resumed his true form and ravished her.
Zeus' final wife was his sister, Hera. Knowing her sympathy for animals, he transformed himself into a distressed little cuckoo, which Hera took in her arms to warm it. At that moment, Zeus turned back into himself and slept with her.
Ganymede (or Ganymedes) was a young man from Troy. His beauty was unparalleled and for that reason, Zeus abducted and brought him to Olympus to serve as his cupbearer and lover. Ganymede's myth is an important step in the history of homosexuality.
Hera. The most famous of Zeus' wives, Hera was also the sister of the father of the gods, and the goddess of women, marriage, family, and childbirth.
Zeus was known in his time as much more than the father of the gods. He was also a womanizer, and as such, he fathered many, many offspring!
II.
Aphrodite later and of her own volition had an affair with Zeus, but his jealous wife Hera laid her hands upon the belly of the goddess and cursed their offspring with malformity. Their child was the ugly god Priapos.
In Orphic myth, Zeus came to Persephone in her bedchamber in the underworld and impregnated her with the child who would become his successor.
In his private life Zeus was quite the lothario, fathering an unbelievable number of around 100 children with many different women (but don't hate him too much – it's just a myth, after all). Of this 100, he fathered a mix of sons and daughters, many of whom were gods and goddesses, and some became great leaders.
Persephone's jealousy suggests she might have loved Hades
In Ovid's famous text Metamorphosis, Hades has an affair with a young Nymph named Minthe. Persephone, now in her later years, was so incensed with jealousy that she turned Minthe into a mint plant.
Zeus cheats on Hera because he's a reflection of the morals of the ancient Greeks. Unlike the Abrahamic god, Zeus was made in the image of man, not the other way around. Ancient Greek men viewed marriage as a necessity and a duty, not a partnership. Women existed to bear children, preferably male children.
Perhaps partly because of the strange circumstances of her birth, Athena is often cited as Zeus's favourite child. He also greatly admired her strength of character and fighting spirit. Some believe Athena was Zeus's first born child, which might, somewhat unfairly, suggest why he chose her as his favourite.
Who did Zeus marry? His sister Hera was the first and only to whom he was married, but that didn't stop him from fathering children with all and sundry, willing or not. Hera, the goddess of marriage and childbirth, constantly fought with Zeus throughout their marriage.
The philosopher Plato recounts that Rhea, Cronus and Phorcys were the eldest children of Oceanus and Tethys. According to the Orphic myths, Zeus wanted to marry his mother Rhea. After Rhea refused to marry him, Zeus turned into a snake and raped her.
Zeus and his many lovers
He was definitely the most adulterous god, though, with his list of consorts and children being the most expansive in Greek mythology.
While the vast majority of Zeus's lovers were female, one of Zeus's lovers was the mortal Ganymede. Ganymede is noted as the only one of Zeus's lovers to whom he granted immortality.
Metis, an Oceanid or sea-nymph, was Zeus's first wife. Wise and prudent, she was endowed with the gift of prophecy. In their early years together, she was Zeus's closest ally and aide, helping him win the battle against Cronus.
But god Eros got hurt by his own arrows and fell in love for a mortal girl, Psyche.
Turns out Cronus had overthrown his dad, and he feared his son was a chip off the old block. One of those who sheltered the infant Zeus was a mountain nymph called Melissa. She cared for the baby and fed him milk and honey.
Hebe was the youngest daughter to Zeus and his wife Hera. Her name came from the Greek word for 'youth', and it was thought she had the power to temporarily restore youth in a chosen few.
The only daughter of Zeus and Demeter (the goddess of grain, agriculture, and fertility), Persephone was an innocent maiden, a virgin who loved to play in the fields where eternal springtime reigned.