Let’s assume horse girls would exist. They look like human girls, but have a tail, hoof hands and equine carpal joints on the lower thighs, so it looks like a horse leg under the lower thigh with hooves. They participate as mating horses where they stand on all fours and gallop like real horses, but they also move around in upright position. They are also taller than humans. Compared to the humans, they don’t need to wear shoes, and mostly run around with only very light clothing or no clothes at all. Alex is a human male, who can shapeshift into a loli horse girl. In his male shape, he is 28 yo, has no horse features and is a dominant and cocky trainer of a team of loli horse girls. They don’t have boobs or pubes yet. As a loli, his body transforms to a young, and slightly muscular loli horse girl, just like the girls he trains. Even as a loli himself, he is still training them. The story contains nsfw, but it isn't focused on it. The training is not public and Alex finds himself watching from the chair.

Alex is sitting on a chair, still in his male form, in a dominant pose, watching the girls train on the racetrack

Girl 1: I'm ready, trainer.