Twilight Sparkle and Starlight Glimmer did their homework, researching the strange and shadowy past of the unicorn memory spell that had saved Ponyville from the encroaching vines of the Everfree Forest. It was then that they discovered the well-kept secret of the extremely frequently used EUV, long thought to mean Equestrian-Universal-Volume augmenter... but which actually meant essentia unicornis virilem...

Unicorn Ejaculate.

Even crazier, Starswirl's potions had additional requirements built into them... requiring EUC to be collected by an alicorn... from a family member!

Follow along with Twilight as the family dinner she'd gone to suddenly becomes an opportunity to gather the critical ingredient that could end up saving Equestria... and see if she is able to resist the temptation to do her duty... and her brother.

She can't.

A submission for the April incest contest.

CONTAINS: Brother/sister incest , hoofjob , blowjob , vanilla , size difference , cum expansion