This is such a good idea, it's a wonder nobody's thought of it before: a butt plug with a horse's tail growing out of the back end. Now, whenever you want to play horsie, just stick that ol' butt plug into your partner's ass, mount up, and ride 'em cowboy (or -girl)! With the butt plug in, your boy- or girlfriend can bend over and be at just the right level to swish that tail on your cock or pussy -- a fairly stimulating experience.
Manufactured by Red's Black Leather, this gadget comes in small, medium and large sizes, and is available through Doc Johnson.