It's just a plain old sweater. Not especially fashionable.

Hoof-stitched and sentimental, but standard as they come. Rarity's seen dozens like it in the stores.

So then, why is it killing her? Why does it send her insane?

It's the mare who owns it—she's responsible. It's the harmless pegasus who's gone and wrecked her.

Rated "sex" for ambiguously fervent thoughts