Twilight and Celestia have been happily married for millenia at this point. Like many other families, children come into the picture. For two immortal alicorns producing mortal foals, this has some rather nasty unintended consequences.
My entry for the Thirteenth Bimonthly Twilestia Contest. The contest prompt was: nuisance.
Cover art is a combination of this image of Midnight Sparkle by MajorCooke and this image of a crying Twilight Sparkle by HSF. The two were compiled together by myself.