They could be impregnated to bear children, but no one to seed them.
That is what the biggest dilemma that the beings of 'Sirius A' faced.
They had been observing the Earth for centuries, from each of their moons, in an attempt to perfect the mould that would encase the breeder of human perfection. They needed to emulate her in time, to salvage their asexual species from dwindling very quickly.
Then one of them had a Eureka moment when it said, "Morose Men of Earth!" and everyone clapped with their eyes.
The journey from 'Sirius A' to the Earth was no impulsive decision. It would taken them a good 8.6 light years one way. But by the time they'd reach home, get started on their new mould and embark on another Earth bound journey, the Earthling notions of beauty would change. From plump ample bodied fuller women, we had suddenly developed an admiration for reed-like girls. When they made huge structural changes to this new proto-type, we had evolved to being lured by the hour-glass body type.
However, this time they got it right.
She was an embodiment of perfection. Flawless porcelain skin that wrapped tautly around her tight muscles. Fuller breasts, a thin waist, and a perfect apple bum, she moved with the swagger of a mermaid who had just found new legs. The only think lacking was the soulfulness in those eyes. How would they replicate a soul when they had none? So they launched her on this mission with a pair of sunglasses, and programmed her to entice a nice sparsely-haired man for his seed.
She waited with baited breath as she spotted our shiny bald beau, and lured him with a pout he would never forget. She led him to a motel room, and sat against the window. Then unwound her borrowed hair and let out a sigh. Cause for a moment, behind that doily curtain, she unveiled a pair of squiggly alien eyes.
** For Magpie Tales