(Literal) Spitroast Mode!

"Oh, this should be fun to watch! Pound-O-Matic, initiate Spitroast Mode! Oh, and you're not going to be needing this..." Myra says and removes your gag.

Then, the machine replies with "You have selected Spitroast Mode! The sexual extremity will be elongated for this treatment, then, it will be inserted into the subjects anal cavity and continuously pushed deeper, until it exits via the subject's mouth. Then, it will begin thrusting the subject until their orgasm. Neither the subject nor anyone else present will question the possibility of this procedure and will simply observe. Beginning transformation and penetration now!"

Right then, the metal rod holding the dildo contracts back inside the box itself and you hear some rumbling sounds from the inside. After a few seconds, out of the hole that the metal rod came out of now came an inch thinner, but much longer version of the purple dildo. It doesn't seem as straight and hard as the previous one, but the length alone was occupying your thoughts at the moment. It was easily over a meter or around 3,5 feet long, and that's more than enough to go through you. There's this weird feeling of excitement within you, knowing that this thing is about to completely spear you. There's also a strong sense of fear and danger, as you realize the possible health risks to this, but hey, you were always a go-getter.

The limp dildo starts moving all on its own, kinda like a tentacle. It freaks you out a bit and your eyes lock on the purple tip that's slithering its way through the air and getting ever closer to your asshole. Once the tip reaches your puckered hole, it starts pressing up against it until your sphincter gives in and the head pops in. You let out a little yelp but observe the dildo carefully, slightly fearing for your life at this point. Soon enough the tentacle-like shaft starts pushing its way inside of you. It tries to get you somewhat adjusted first by sliding a few inches in and out of you. You let out slight moans as the shaft brushes against your prostate elegantly, slowly building up your erection.

After a few minutes of thrusting 6 or so inches in and out of you, the shaft moves a bit deeper down your rectum. It takes it somewhat slow, so you get some time to adjust to as it travels up your anus. Although the further it goes, the louder become your moans. Slowly the dildo moves 9 inches up your ass, noticeably bulging your stomach. After another while, it's 12 inches deep inside you, tearing up your eyes from the feeling. Slowly it goes deeper and deeper, barely giving you a chance to adjust.

Around 10 minutes later, the purple snake is around 2 feet up your butt and wriggling further. You feel it forcing itself deeper inside you going deeper than anything else has before. Its still sliding in and out, brushing against your sensitive prostate and getting you hornier by the second. As the toy slithers even deeper, making you experience feelings you've never had before, you can swear that you can feel the thing up at chest height. You can even see the bulge moving up between your nipples and back down as it goes in for another thrust. Soon enough, you feel pressure from within your throat. It feels like being throatfucked, but without even touching your mouth or triggering a gag reflex. At least not yet...

As the dildo moves even further, creeping up your throat and reaching your mouth, it suddenly thrusts forward and shoots out of your mouth. You gag, from the feeling of being deepthroated, even though the cock is coming from the other end.

You see the tip of the rubber shaft rise 6 or so inches out of your mouth, and then the machine says "Complete penetration of subject successful, waiting for an orgasm." then, it starts thrusting you again.

The slippery toy moves back into your mouth and slightly down your throat, before shooting out again. This feels weird, to say the least, but something about this is getting you turned on. Maybe it's the constant prostate stimulation or maybe the feeling of being materialized as just a sex toy. Either way, you're starting to love this more and more as time goes on.

After a while of pumping you, the machine speeds up, as if trying to get you to cum faster - and it's working! You try to moan, but all that comes out are gargled sounds of spit flying out of your mouth. After pounding your ass for over 10 minutes, you feel yourself getting even closer to orgasm. Your eyes squint shut, your cock throbs and your irregular breathing picks up as you feel pressure building in your crotch. After a few more thrusts, you can't take any more and shoot a giant stream of jizz in front of you. Your orgasm is accompanied by a loud scream and a slight thrusting of your pelvis. A few seconds later, your orgasm dulls down and the machine stops its movements.

You hear it say "Subject orgasm recognized and full penetration accomplished. Terminating processes..."

The spit covered tentacle quickly slides out of your body and back into the black box it came out of, leaving an empty feeling inside of you. You take a few quick breaths before Myra slaps the gag back on your face.

She leans over as if inspecting you and says "Huh, seems like you took that very well. You even managed to cum pretty fast, which isn't something that happens a lot. Watching that display got me a bit excited myself, so let's move on..."