The vile King Sombra placed a curse on the ponies of the Crystal Empire, rendering them all sterile. The seven rulers of Equestria, Celestia, Luna, Cadance, Twilight Sparkle, Nightmare Moon, Molestia, and Chrysalis are at something of a loss on what to do about it... when Chrysalis comes up with a radical solution.

Adoption. And to make sure there are enough babies for everyone in the Empire to adopt, a fertility potion will be used. One that will make the mare in question absurdly fertile, capable of giving birth to hundreds of babies painlessly. It seems like a good idea, and the seven princesses begin to look for volunteers.

Then Discord takes the formula, increases its potency, makes it airborne, and releases it into the atmosphere.

Sexy hilarity ensues.

(Transferred over from my now defunct Fanfic Fetishist account. Story is scheduled for a major rewrite.)