Twilight really should've known that asking an oversexed Rainbow Dash for help with her experiments would eventually result in getting violently fucked by the hyperactive pegasus. A small mishap during an experiment gives Dash the ability to control the mind and actions of her friend, and things go about as well for Twilight as one might expect in a situation like this.

Contains: soft mind control, dominant futa Rainbow Dash, bondage (kind of), facesitting, titfucking, benis in bagina.

A commission for superfun.
Also, I'm entering it as a submission to Dirty Little Secret's Dirty Little Contest.

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Edited by Exuno.

Cover art is a crop from a (NSFW) picture by ImpracticalArt. Derpibooru id: 831445.