Show her directly who is boss

"Very good choice, John", says Ashley's mother.

"But what's the best way of doing that?", you ask.

Ailani hesitates a little, "We'll with bi-pedal horses, I guess it's sex, unless you don't feel like it. I mean, nobody would want to invade your sexual self-determination just to train a filly."

That's nice of Ailani to be concerned for your modesty. She obviously is a lot less concerned for Ashley's modesty. Well, you certainly feel like it. You just smile, and give Sarah and Ailani the remaining tools, and take the line to Ashley's collar.

You go to Ashley, pulling her to you, using the bridle so that she directly looks at you. "So, Ashley, we got you as our new filly now properly bridled. It's now time to start riding you. We'll do a proper training, but first, I am going to mount you." While Ashley is staring at me, her (former?) friends put cuffs at her ankles, and attach lines to the rings in the cuffs. You continue "Do you agree with that?" She violently shakes her head.

"OK, let me be very specific. I am going to have sex with you. Will you cooperate?" Again she shakes her head. "But, I explained to you that this is part of the speciesim experiment. Don't you agree?" Again, she shakes her head and even tries to pull away from her.

Ashley's mum says: "Well, this is quite usual, that young fillies don't want to do their jobs. I hoped this bi-pedal filly would be more able to understand. I thought I raised her well, and she is usually not stupid, but this is just ridiculous. I am sorry, John".

"No worries", you answer. Then you take the belt cutter and cut away Ashley's bra and panties, letting her nice boobs spring out of her bra and showing here nice black bush. Ailani points you to the stable, and you pull her with **** on her bridles. Arriving in the stable, there is a bed of straw. Sarah and Ailani unlock their hands from each other, but leave the cuffs on the wrists, and bind them to two posts of the box. You and Ashley's mum take the ropes from her ankles, and fix them.

Now she lies beautifully in front of you, on her back, gagged, arms spread and her legs pulled apart by the ropes attached to her ankles. She can still move her hips a little back and forth, but at the price of further opening her legs.

Sarah and Ashley's mum leave to give you some privacy, but Ailani asks "You know, I'd like to learn more about handling bipedal fillies. Do you mind if I stay, John?"

"Yes sure, this is all about experimenting and learning. Why don't you already lube her up, while I get ready? The lube is in the pack where the cuffs and bridle where."

"Sure." Ailani takes the lube and approaches her former friend. "Ashley, so let's get you ready for your first mounting.", Ashley tries to move away, but Ailani rubs the lube all over her vagina, talking soothingly to the filly. "You are going to like it. I know you haven't done this in a while, and you told me you were looking forward to fucking your new boyfriend over the weekend. So this will be even faster."

Meanwhile you get rid of your clothes. You hold your shirt in front of your cock, so not to irritate Ailani. "Don't worry about it. I guess this is going to be part of handling bipedal fillies. I appreciate the gesture, though", she reacts to this and then walks behind you.

You drop the shirt and walk between Ashley's legs. Your cock gets even harder, when you start fondling Ashley's breasts and hips. The ropes allow her some movement, but only so much.

As you approach her cunt, she is pulling away from you with all her ****, you can feel the strain in her leg muscles, but the ropes hold.

Slowly you move the tip of your cock closer and closer to her vagina, until she cannot move away any further, and then you grab her hips and sink in her with one long thrust. Oh, this feels good! She stops fighting it, having exhausted her strength. You continue to fuck her, and very shortly you come close to your orgasm. You smile at Ashley, she knows what is happening, and tries again with all her **** to stop you. Having her wiggle below you really adds to the pleasure. This really brings you over the edge and you come in her, filling her with you sperm.

That was really nice. After a few minutes rest, you do it again. But before Ailani, who has been observing meticulously, optimizes the ropes to make the experience even more pleasurable. (At least for you. She didn't consider how it feels for Ashley, of course.)

A few days go by where Ashley gets settled in as filly.