Right there, right at the corner crease where her two ass cheeks meet, you see a tail extending from Lyra's backside. Her tail curls upwards in a little loop-de-loop, and at the end of it is a little tuft of hair that's the same ginger color and wavy texture as the hair on her head. It reminds you an awful lot like a pig's tail. It wiggles and bounces around as Lyra thrashes against the bars of the gate, almost kind of cute the longer you stare at it.
Of course, that tail isn't the only part of Lyra that seems to have grown, you notice. It's a little tough to tell from how much they're wobbling and clapping, but her ass cheeks seem to be swelling up inches at a time. As her butt grows bigger and juicier, her hips start to widen to accommodate all the new fat meat accumulating on her from seemingly thin air. Her thighs are getting in on the fattening action as well, swelling up like thick pork sausages dusted with adorable freckles. All these gains piling onto your classmate all at once... you're stunned into a silence and unable to hold back your arousal anymore, your penis now so stiff and tingly that it honestly kind of hurts.
Eventually Lyra's screaming obscenities start to grow hoarse, and the energy she had for rattling the gate of the pen seems to be dying down. With a huff, she turns away from the gate, frustrated with her protests going ignored by whoever put her and you in this situation. You notice that her nose is starting to tilt upwards and flatten at the end, a lot like a piggy snout. Despite yourself, you can't help but think she looks cute with it. Of course, now that you're looking at Lyra's face, you notice her gaze locked firmly on your crotch. Her expression is unreadable.
"Ah... right," Lyra sighs, rolling her eyes, "Not much we can help about getting hot and bothered around me right now, huh?"
"Wh-what?" you stammer.
"Look, I get it," Lyra assures you, waving it off, "and I don't blame you either. We're both naked and you probably think I'm sexy. It's only natural you'd get hard around me, and there's not much we can do about it right now. This is just your body reacting to mine, it's natural and it's not your fault. I'm not gonna beat the crap outta you just because you're a straight guy around a naked girl, okay?"
"O-okay," you pant out, "Thank you, I guess. Uh... Lyra? Could you do something for me real quick?" She started blushing hard at your question.
"H-hey, listen you!" she backs into the gate and points an accusatory finger at you, "Just because I'm not freaked out by you getting aroused by me doesn't mean I'm down to fuck you right now! Especially given the circumstances!"
"No! No, it's not like that at all!" you yelp, waving your arms in a frantic "NO" gesture, "I just want you to touch your nose real quick?"
"Why?" Lyra blinks, reaching up to touch her nose, "Is there something strange going on with myyyyyyYYYYYY-!" A look of terror spreads across her face as she feels the shape of her little pig snout, and her whole body breaks out in a cold sweat. "MY NOSE! I-i-it turned into a piggy nose! Did... am I...?" She starts feeling around her backside until her hand meets her curly little tail. She goes absolutely pale, and her face turns a chilly blue. "T... t... tail..." she whimpers.
A thought suddenly comes to your mind. If Lyra's suddenly grown some piggy traits, then are you starting to exhibit some of your own? You feel around the base of your own spine and discover...