Rarity is interrupted from her work by a very noisily moaning Sweetie Belle, who should be sleeping. Rarity knows that her sister is a rare kind of filly, and her first estrus would be especially brutal for her. She soon discovers her sister's condition after checking in on her, finding that Sweetie is indeed in her first estrus, and that her special biology is making her absolutely miserable. With Rarity being the Element of Generosity, and also in her own estrus, she gives her little sister the only gift she can at that time.

Herself.

In the process, Sweetie also gives her sister a rather unexpected gift, too.

~

This is my second submission to the Incest is Wincest! Siblings Incest Contest

Contains: Masturbation (penile and vaginal) by a herm/futa, consensual incestuous sex between a futanari foal (filly with colt parts) and her regular, adult mare sister AKA foalcon, a mare and a filly in heat, pheromones/scents, painless loss of virginity (filly), use of a sex toy (vaginal), excessive cum (in proportion), internal cumshot, post-sex cunnilingus, including eating one's own cum, and highly likely inbreeding/impregnation. Pretty tame, considering. All acts performed are totally voluntary by both parties. Also, the age is left ambiguous intentionally. Do as you will with that fact.

~

Credits:

Written by me, LegionofPony. Edited by LGZ.

Coverart is a snipped and combined version of elements from images #1758119 and #1758119 (both NSFW) by 'alcor' on Derpibooru.

This story is also heavily inspired by image #1613305 (NSFW) by 'wyntermoon' on Derpibooru, but with a character obviously changed.