Spike has a problem: he's eating Twilight out of house and home. Literally.

His adolescent draconic biology is violently making up for years spent as a stubby wyrmling, and it won't be long before even the library is too small to fit him. Meanwhile, Rarity's coming off of a rebound relationship, and just happens to notice her friend's growing physique. It'll take all of Twilight's power to convince her that a relationship with a "giant, musclebound hunk of a dragon" might not be the best idea when said dragon may soon be able to crush her like a twig.