Your and Lyra's long donkey ears are standing tall and focusing themselves with pin-point accuracy onto the creaking door and then the footsteps that are now inside the barn. Your tail flicks again but you ignore it. Finally, a large man in a lab coat steps into your field of view.
"Well, well, well, if the two lovebirds aren't coming along nicely," he taunts, grinning at both of you.
"Dr. O'Tanner?!" shouts Lyra as soon as she can find her voice again.
You ask the question you and Lyra both want to know the answer to: "Why are YOU here?"
He laughs and says, "This is my barn, or rather it's my step-father's barn. He raised me to understand animals and agriculture and then sent me off to college, and now I teach and do research. He still looks down on me compared to his so-called REAL son who's going to inherit this farm, but that's going change as of today! I've discovered something that will make him millions, a serum that can make a farm animal out of any organism. And if he still doesn't appreciate me, well I'll just reveal it, patent it, and sell it, then I'll make millions!"
You sigh with relief. "So that means after you prove your little experiment works that you can change us back, then, right?"
The scientist looks at you. "Why would I change you back? I wouldn't waste a fertile pair of donkeys like that, and besides, I want to keep this our little family secret if my step-dad will finally accept. We wouldn't want you to say anything, now would we?"
Lyra grabbed the locked gate of the pen and asked, "But why us?"
Dr. O'Tanner shrugged. "What can I say? You were both so drunk after whatever frat party last night, and you both happened to stumble past my research lab, it was trivial to invite you in, inject you with tranquilizers, inject you with the serum, and dump you in this pen. I had been about to use another one of my lab animals, but well, those are expensive."
You stumble to your hoofed feet and wobble to the gate, taking your place beside Lyra. "Please, Dr. O'Tanner, we won't tell ANYONE about this! You have us both in your intermediate bio class, right? If we tell then you can just flunk us."
Dr. O'Tanner laughed again, "Oh you silly donkeys, you weren't going to pass that class anyway." He pulled out a pen and clipboard and continued, "Okay, to document, so it looks like the ears have grown in well, back legs have formed but the forelimbs are still human arms, tails have grown out, and nothing else yet, I thi--wait, is that semen dripping out of Lyra? Nice job, stud!" He winks at you and makes a note on his clipboard.
Lyra is furious: "We couldn't help it, you bastard!"
You agree with her, "Yeah, I smelled something, and then, well, I don't know, I just couldn't stop, and she couldn't stop peeing, and I don't know I--"
The professor interrupts: "Ooh, that sounds like your equine pheromones are starting to kick in. I thought maybe you were just that into each other and horny, but this is good to know. Anyway, I'm going to set up this camera, and I'll be back to check on you in two hours. I've got that stupid undergraduate biology course of yours to teach. Looks like you two will be skipping class today. Tata!"
The tripod was set up. The record button was pressed. Then Dr. O'Tanner was gone. Lyra hurled profanities the hole time, except when she interrupted herself with they occasional donkey bray. The scientist jotted something about that down on his clipboard, too, before he left. At last, you and Lyra were left alone again. You were huddled in the corner embarrassed that you were partially a donkey and that you'd had sex with Lyra due to something eerily different from your own free will. You bring your tail around beside you, pick it up and stare at it. "Am I just going to be some donkey stud?" you ask to no one. But Lyra answers: "No, and you'd better get your head out of your ass before you become an ass. We're going to beat this, and that crazy scientist is going to be so screwed he won't know what hit him. You'll see, we'll---ugh," her voice trailed off in a grunt, because something was happening. Apparently, you're both changing again.