Lean

Smart breeders know that you want to avoid knocking up all of your girlfriends at once. In theory it sounds amazing to have three massively pregnant girls in your house all at the same time, and it is--right up until they all deliver at more or less the same time. Then you've got three exhausted new moms, none of whom you can fuck for at least six weeks, and of course three newborns to deal with.

By staggering your impregnations, you can ensure that always have at least one hormonally charged, full-bellied fertility goddess available to play with at any time, any since their offspring are still growing safely in their bellies, they can help take some of the workload off of your post-partum girlfriend.

Plus, there's also something very primally satisfying about comparing the differences in the bodies of your various lovers as they all joyfully carry your seed at various stages. From the tiniest changes all the way to their fullest and most gravid, them being pregnant with your children makes them perfect in your eyes.