Her brother GEB is the matching God of the Earth. He is also her husband. There’s a crude illustration of them doing something rude which pops up all over the place. She is doing the upper bit, and GEB, although much smaller than her, is rising to the occasion...
She’s never alone for a minute as SHU the Air God holds her vast body in place. And every evening the Sun God RA enters her mouth and wanders around all night inside her body before emerging from a place you can probably guess.
NUT and GEB desperately wanted children, but they had many family planning problems, as you can imagine. Worst of all, RA put a spanner in the works by placing a curse on NUT’s offspring. (Don’t ask us why; he refuses to talk about it.)
"You may be pregnant," he said, "but your children will never be born, not on any day of any year."
The heartbroken NUT turned to THOTH for advice. His famous dice game with IAH uncovered an ingenious loophole in the curse, and NUT was able to give birth to ISIS, OSIRIS, SET and NEPHTHYS. Which is just as well because Egyptian mythology would be pretty dull without them.