A muscle relaxant

The researcher down your throat pauses for a moment with your face pressed into his pelvis while he flicks the air out of a needle. The pain in your rear continues to grow with John's expanding cock, so a shot of anything that might help sounds like a good idea to you. The researcher tells you to hold still as he slowly humps your face while aiming the needle at your arm. You try the best you can under the circumstances, and after a pinch... nothing?

Your blinking suddenly seems difficult and your breathing, already hard enough with a cock lodged in your esophagus, becomes even more shallow. You try to pull your head back to get more air, but find the movement next to impossible, even without the researcher holding you down. The pain in your ass and throat are slightly less than before, but only because your entire body feels like jello, so you can't even tense up for the remaining pain.

"Aw, man! This is way easier now," John remarks to your father as he picks up the pace thrusting into you. "I'm almost back up to my normal size now!"

The man down your throat has called over another researcher, and they've begun taking turns forcefully jamming themselves to the hilt while at least pretending write down comments on things like increased elasticity and malleability. Soon all pretense is gone and they are passing your head back and forth like they are sharing a sex toy, viciously yanking your loose neck back and forth by the hair with no regard for how it might feel to you; and it felt like they were trying as hard as possible to give you whiplash. You attempt a scream, even if gagged, but only a little extra air manages to flow from your nose over the wet thunk of your brutal throat fucking.

"Goddamn! Her throat is like a wet cunt!" The researcher down your gullet exclaims, demonstrating the ease he can move in and out of your throat by repeatedly slamming your face into his crotch at full ****. Between this and John's still growing cock pounding into you, the pain is excruciating. Tears stream down your face to join the waterfall of saliva falling from your chin.

"Hey! Don't call my daughter a cunt!" Your father says to him sharply.

"I didn't say she was A cunt, I said her throat is LIKE a cunt." He replies, still slamming your face with a quickening pace. He looks down at you. "I would never call this sweet little angel a cunt, now would I?"

He smashes you one final time before giving you a second injection, this time in the way you're more used to. You feel each wave on your tongue and down your throat as it travels through his cock on its way to filling your stomach. His only movement is to grind your face slightly harder as he shoots into you.

"Yeah, well... Watch your language." Your father says back. He turns his attention back towards John's cock. "Wow, it really does get bigger every time, huh? How big do you think it will get this time?"

It's already past the point that it choked you **** earlier? And it's still going?! You try desperately to tense up or make some sort of complaint about this, but the researcher shooting down your throat simply passes your limp head to the man next to him with out a care. The second researcher slides easily down and quickly begins rabbit humping your face for only an half inch or so with your nose pressed into his pelvis. You're surprised you can still draw breath so easily. You wish you would just pass out.

"Well at least the **** she took is working well," John says, still fucking your ass with his now cartoonishly large cock. He holsters what feels like a pringles can, only somehow longer, all the way to the hilt inside you. "I can't believe how easily I can slide in this whole thing!"

The man humping your face suddenly pulls out and jerks himself off directly on to your tongue with short oozing spurts. He bends down to put the rubber stopper back into the ring gag, then whispers in your ear that he still thinks you're a cunt and walks away. You try to swallow the copious load trapped in your mouth, but find this too impossible. You're stuck with the constant taste of cum and the pain of the log stretching out your asshole.

"I think that's probably about as big as it's gonna get." John says, and begins thrusting with more purpose as he starts to wrap up. "Ugh, I think it loses feeling as it gets bigger."

Your brain explodes into even more pain than you thought possible as he starts an unreasonable pace to counteract the loss of feeling. You feel on the verge of passing out, but it never comes. After what feels like an eternity of **** John finally pulls out his gigantic cock and brings it over to your head while jerking it with both hands. He leans forward to aim his load at your mouth.

"Oh shit! The stopper!' John exclaims, removing one hand to try to quickly pull out the plug, but he's past the point of no return. The first shot alone seems to cover half your face with a massive wave of cum. After seven or eight shots of equal size you are unrecognizable under the white mask of the wasted medicine. Every inch of your face is covered like you just finished a one man bukkake film before he can control himself enough to pull out the stopper and ooze the rest inside.

The cum under your nose finally does the job of cutting off your breathing as your father storms off to yell at the research who put the stopper back into your mouth to blame him for the wasted dose. John goes to busy himself with fitting his oversized cock into his pants, leaving your mess covered face alone to suffocate.

You try to blow your nose clean or swallow several times before giving up. You wanted to pass out anyway. Why couldn't it have just been earlier? Your mind fades...