Well, she is right, babies do need that. You get to thinking about your life, you haven’t really had the chance to actually experience a real childhood. You grew up in an orphanage in a poor neighborhood, the kids in that orphanage all bullied you. Maybe it was a subconscious need for a real life, and this was your chance to cash in on it. “Who’s going to take care of me then Jenny, you can’t leave a baby alone.” You are already regressing, now more of a teen than an adult. Jenny looks you in your eyes, “Is that what you want? You want me to be your mommy?” Suddenly, a wave of emotions hits you, you can’t look her in the face as you blush. When you were an adult, that was exactly what you wanted, but now you can’t express that. Jenny pulls out a different bottle and says, “Here, this will solve all your problems.” You hesitantly take it and start to drink from it. It’s thick, like a milkshake but warm. Your senses dull as you feel like you’re drifting off to sleep. Jenny gives you a kiss as you fade.
You awaken in a pile of hay inside what looks like a barn. You look down and see your hoof-like fingers and furry arms. You get up onto your hooves with some difficulty. You are much shorter and smaller than you were in human form, but somehow your dick is larger. You are still wearing the diaper, but it feels less like a foreign object now. You stumble around the barn until you finally get your footing as you look for your mother. A familiar looking horse woman trots your way. Her mane is longer, she is much more well-endowed, and she’s even put on some weight as you can see in her belly, ass, and thighs. Her voice sounds older, but you can tell that she’s your mother as she says, “Rise and shine my little stallion.” You walk up to her and put your lips right on her nipples as your drink more horse milk. She even holds you as drink, being the loving mother mare that she is. Once you finish, she puts you back down as she goes to a nearby pond and drinks water. Her ample rear and tight pussy is on display for any stallion to see, but it doesn’t mean anything to you. Her tail flicks as a massive PFFFFRT escapes her tailhole, no shame on her face at all. Your mind is filled with memories of her nursing you, teaching you basic knowledge, her helping you walk, and her telling you that horses are known to be smelly. You grunt as you release musky piss into your diaper, you are a good baby. You wanted this more than anything else.
You become a colt that wears diaper while Jenny grows into a MILF, caring for you better than anyone else had. She feeds you, cleans you, and teaches you how to be the best stallion you can be.