Rainbow Dash decides to test out a potion that Twilight has been working on for a while. The effects are supposed to control a mare's desires when in heat. However this potion has a different effect on her. An effect which Princess Cadence offers to help her relieve.

(This is a commission done for Mr. Ghostman if you like this story and would like me to write you one, just PM me. I don't charge for my commissions X3)

(Contains: Futa, Cum Inflation, Thigh Fucking, and light musk)