Prescription: Sodomy?

As Alex finishes pleasuring you up to a nice thickness, she's not slow to put you to 'good use.' She flips herself around and perks her ass out for you. "Sodomy once a day keeps the anxiety away, my anatomy professor used to say," she hums as she rubs her inviting asshole up against the tip of your dick.

"I don't know if I believe that, or that your professor said it, but I'm not a doctor," you say as you tease her a little, rubbing your dick a little around her vulva and clit, causing her to momentarily whine, before returning to her asshole and slowly push yourself inside of her. You could swear she's just getting tighter every time you do this, but she seems to be just as happy about being filled.

"Well... it depends on the patient, but sex is a great stress reliever... and in porn university you have some cute and pervy professors," she says slowly between moans.

You would have called her out on the absurdity of 'porn universities,' but you find your motivation to fuck and grunt higher than your motivation to request an elaboration. She merely smiles at you and within a few more minutes she orgasms loudly. Her ass clenches around your dick and drags you along for the ride, making you cum moments after her. And... you realize you have a surprising amount of splooge in your system. Obviously much more than you had before you realize as you count your fifteenth burst into her asshole.

With every burst, you feel your nuts contract and they feel as if they're growing with every pulse. And when you finally stop, you feel your nuts seem to be taking a lot more space between your legs than before. You slowly begin to pull out, Alex' continued orgasm starting to abate, and you pull out what certainly must be a lot thicker dick than what you put into her. Seven inches, eight inches, nine inches? As the head pops free, you find yourself the owner of a demi-human eleven inch long and two and a half inch thick at the middle sausage. A godlike creature compared to your old six and three quarters long and one and a half thick junior you had a few days ago. And your balls are now the size of double yolk chicken eggs.

"Holy shit," you whisper as you lift it up with one hand in awe.

"Oh, my..." Alex sighed as she seemed to regain her mental capabilities. She gave your dick a curious look. If you hadn't just fucked she'd probably give it a hungry look instead of the more curious and awestruck look she was giving it now. Almost motherly...

"This is your doing, isn't it? You made me grow a bigger dick?" you asked in a slightly accusing tone. You were a bit angry at being changed, but compared to the changes earlier in the day, this was admittedly a step in the right direction.

"Oh, well... I think so?" Alex smiled as she turned around and happily sat her filthy ass down on her desk with a squelch. "I had a theory that thoughts and desires seem to effect the... effects of these infected items. And, assuming we're both infected now, we're easily manipulated. The upside though is that we can manipulate other things as well!"

"So this was planned?" you ask as you begin to pull your underwear back onto yourself, stuffing your still slightly stuffy man meat and ball sack down into a comfortable position. You realized that this was going to get uncomfortable when you put on your jeans with a half erect dick along one thigh, so you picked up and folded your jeans across your forearm instead. Were you... thinner and bigger than before as well? You lifted up your t-shirt to look at your beer belly, and it sure seemed less chubby than before.

Alex got distracted at the show for a moment. "Uh? Oh. Yeah, I was sort of thinking 'Make Jamie hung as fuck,' while you were pounding me. And I think I felt you grow inside of me, but I was totally not paying attention at that moment. I'm sort of surprised I didn't tear at the size of it."

"Maybe you made yourself capable of taking foot long dicks in the ass with no repercussions in the process?" you ask as you sat yourself next to Alex on a dry part of her desk. "Considering your new medical background from 'porn university,' I don't know if I want to know where we might end up at the end if we let you experiment on me."

"Aw, don't you trust me?" Alex asks as she caresses her tits and gives you one of her winning smiles. "I can guarantee you, my thirty minute old medical degree is as authentic as your dick," she continued before she gently patted your new manhood for effect. "As long as we keep our references clean, we should be safe, right?"

"Right...but how are we going to be able to know if they haven't been compromised, like your original notes?"

Alex hummed in serious thought at the problem, and you could imagine that if she had been wearing clothes, like a white coat and something slightly moderate but still showing off her curves, you'd probably concede she would appear professional.