Nut and Geb
Nut, the goddess of the night sky, and her brother Geb, the god of the earth, were originally thought to be in a constant state of love making. Ra grew angry with his grandchildren, and commanded their father Shu to separate the two lovers. The god of the air took his place, and trampled on the ithyphallic Geb, and lifted Nut high into the air. Nut was found to be pregnant, and was then cursed by Ra - she would never be able to bear her children on any month of the 360 day year. Thoth managed to win a game against Khonsu, god of the moon, and used some of the light of the moon to create five extra days (making the year 365 days). During those days Nut gave birth to her five children - Isis, Osiris, Nephthys, Set and Horus the Elder (not to be confused with Horus, the child of Isis and Osiris).