There's a bit between your teeth, fixed to a leather harness around your head, and reins which rest between your shoulder blades. It keeps your mouth open, makes you drool uncontrollably. Around your hips and thighs is a similar leather harness, a handle in the small of your back. You're in pony boots which make you teeter around, keeps your arsecheeks pert and clenched, on display.

Anyone who so wishes can grab the handle on your back and pull it, unbalancing you, allowing them to lower you like luggage, onto all fours so you're presented and available; they can take the reins which rest on your back and pull them taut, arching your back, pulling the bit deeper between your teeth. Like this, you're perfectly ready for them to mount you and breed you.

Teetering around, in full knowledge of this fact, makes sure that you're soaked and swollen, and that they'll encounter absolutely no resistance as they force their way balls deep into you.