Cumthym+

"So, what exactly is this?" It's a valid question from Yuri, you weren't entirely transparent about your intentions. Yena said she was prototyping her guitar, that it was 'electrifying' and 'mindblowingly orgasmic'

So Yuri, fairly or unfairly assumed that was about music.

Technically, she's not wrong.

However, in practice. Yena is synced up to a device that can only be described as a bondage lover's wet dream. Wire's everywhere, some coiled to her thighs, some dangling off her chest. A lot pooling to almost make a tailor-made dress.

"It's one of our new inventions." Yena remarks casually, like there's not a dildo that can self-thrust next to both her pussy and her tight ass. Like there's no vibrating clamps that gently hug her nipples. You have the guitar in your hands, though you'll definitely pass it to Yuri in a little while. Need an unbiased tester, make sure it works fine.

"Last time you told me about your inventions you were making fuel-powered bouncy balls. What even happened?"

"We wanted to pay bills, this is our latest idea." You interject. "It works about as simply as you can expect. Each of these four buttons resonate with another. You play any song you know and see how the woman reacts."

"Show her practically, come on." Yena sighs, you are down. You click the first button, the clamp on her left nipple starts to vibrate, squeeze slightly– gets a short gasp out of Yena. Same for the second just for the right side.

The third one is more interesting, you only do short presses first– make sure to not overwhelm. The toy pushes deeper into her pussy, sits inside until you make it move. This is designed to be easy to use, hard to master. Replayability that can get even the most diehard of rhythm players to get invested.

It's a very specific niche your targeting, rhythm players good enough to do well that also have a partner. Eh, it'll reflect in the mark up.

"Come around." You point, Yuri follows and looks at Yena from behind. You click the last button and it pushes deep inside Yena's asshole, you push it a bit further. Then she stands there filled to the brim.

"Right, I still don't know why you needed me to be here? Me and Yena are close, don't get me wrong. But this is–"

"Oh shut up, before I met him you had your tongue in me every other night. We are definitely that close." Yena cuts through Yuri's lies, she's red as a tomato and doesn't say anything more.

"We need an unbiased participant who doesn't know it inside and out, you are that person." It's a simple exchange, you'll buy her a nice meal for this.

"Okay, sure, fine. Show me it." You've already started, but there's a few other cool features you can't wait to show in more detail. Then, your television screen turns on. (thanks to a hidden button in the frame, otherwise it'd ruin the IMMERSION!)

"We've made it so this guitar can work on all forms of rhythm software. We'll use Fortnite Festival for this because we have it installed." You swap to a song, you need to pick one that's not too hard, not too easy. A perfect highlight, you pick a 7/7 on bass. Should be easy enough.

Here goes nothing.

The music starts to play, though what song is hardly relevant. What matters is Yena braces herself for the first set of notes, though no matter how hard she braces. It still catches her off guard, hitting all four notes at once. Multiple times, the two dildos fucking her holes as her nipples get tormented.

"Ah, fuck!" Yena's caught caught in pleasure, Yuri's blushing. Her friend's got 14 inches (divided by two obviously) inside her and they are drilling her while the person causing it is just strumming a few cords. That's normally a metaphor, but these two inventors be doing stuff differently apparently.

"As you can see, it's quite intense." You lull, hitting your keys to the beat of the music. You can hear the slick noises of her pussy getting thoroughly fucked cutting through the rest of the noise.

"Y-yeah, I–" Yuri is rubbing her legs together, looking up towards the sky as if focusing on Yena is going to make her lose her mind. Her body's sweating under pressure, hands gripping her thighs to avoid them going anywhere else. "It's something."

"Ngh, fuck! Yuri, touch yourself for me– please!" That came out of nowhere, the machine must be have sparkled something. "I don't care he's watching, come on! Please–"

"What?!"

"You don't have to–" You start, your voice trails off because a particularly hard section comes up. Forcing your entire attention, it reflects in Yena's moans. Hits a crescendo that lasts for a solid half-minute.

"Ignore him, do it, let me see your pretty pussy again! It's been so–long!"

Yuri's between a rock and soft place, this wasn't in your initial testing plans but errant data should probably be considered. In the event they got a three player rotation, someone touching themselves is standard, expected.

You just never designed this for three people.

Fool's mistake and in this case, you're the fool. Yena's on cloud fuck knows and therefore doesn't have time to worry about all that. But back to Yuri's ultimatum, surely with the way she shouted what she'd be thinking about it still ri–

Oh, she's wearing less clothes than before.

Hm, oh well.

The problem with your technology you are realising now is you can not focus on your test-partner being so overwhelmingly aroused that her arousal is being launched into the floor. Nor can you focus on her situationship best friend heeding her commands. Hastefully kicking herself out of her shorts and underwear simply and efficiently. Put blandly, your peripherals are doing quadruple overtime.

A few more seconds, the song will be over. But this is the most ridiculous section for Yena, a bunch of hold notes. When the buttons are held the machines work at peak efficiency, fucking the soul out of her. "Oh my, my, fuck– yes, fuck!" Her orgasm hits right at the finish of song, and it's explosive. Spurts of squirt painting a new pattern in your favourite towel.

You play an imaginary song, fuck her insane ass (You'd know, it hugs you like the warmest kindling of affection.) with chords to ride her through it. Then perhaps the most annoying thing happens.

Your frame snaps, the thing keeping Yena from falling over ages ago breaks in two and unsurprisingly she slips. Right between Yuri's legs, face first into her box tongue first. Yuri is quite to take advantage of such a perfectly shown moment of chance, grinds her slit against Yena's pretty face. She quickly sticks her tongue out, devouring her friend while you stand there and savour such a moment.

"Yena! Eating me out so, god, damn well!" The machine is still mostly plugged into Yena, so you do Yuri a favour. Pushing a few buttons that make the girl moan straight into her– resonating within her core. "Don't stop!"

Muffled moans fill the room as you continue to pleasure Yena, pumping the machine's dildo in and out much slower now. Just a consistent rhythm enough to mess with her brain, overwhelming without shutting her down. You need the data. Whatever is salvageable out of this. You stand there bricked up like a virgins first time seeing tits, rubbing yourself through your clothes.

Yuri's moans are ridiculous, hits the walls and bounces back twice as fucking loud. Then you think, you need more data… someone who hasn't been responsible in the design process. "Yuri, say– would you like a turn?"

She looks shocked, but Yena pulls herself away to breathe. "Yeah, you trust my creation right?" No, she definitely didn't. It snapped in front of you. "I'll hold you up."

"Okay, I trust you, for once." Yuri's words brought you two great joy, helping Yena out of the machine and slowly putting Yuri in. Lubing up her tight rim, giving it a finger while Yena gave it two. Working together to make sure she could handle this, proper procedure. (proper bla bla you get the idea by now surely.)

Couple minutes later and it's all set up, Yena holding Yuri up by the armpits to ensure she doesn't replicate her fall over incident. "Ready?"

"I guess?" Yuri is not nearly as assured as Yena was, after seeing the mess that was just made and getting herself ate out though she is far too horny to think logically about this. You pick a song that honestly you just like, Fantasia For The Witch's Hound.

"Don't let her go, I don't know how concussions and orgasms mix." You warn, however Yena is gripping onto her harder than she grips around you so it'll be all gucci. " Here goes nothing.

You start, and this song is absolutely nothing compared to the last one– difficulty erect and ready to go right off the get go. Triple click every note in rapid motion, she's already had her warm up. Shaking and struggling in Yena's grasp, who is doing her divine duty as best she can. Going above and beyond as well– kissing Yuri's neck like it's a fine treasure, letting her teeth scratch against the soft skin.

"Ngh, Yena! This is so over–" It's hard to articulate the beauty of the situation, maybe you've struck gold with this. Market it as a swinger's party device, make millions. While your salivating over potential profit (pp for short) Yuri is salivating at the pressure, crotches stained with both of their arousal intermingled as one slick layer.

"Overkill? Overwhelming? Overtastic?" Yena breaks the rules further, rubbing her clit feverishly, giving Yuri the time of her life. "Take my cocks, fucking you– like old times sake. Cum all around them!" You are the voyeur to time long past and only now you get an idea.

What if you just, stood to the left? So they are directly in your line of sight? Incredible.

"Okay!" Yuri takes Yena like the good girl she clearly is. "So, fucking full!" You stop playing the song, hold down every button to overwhelm the girl. She loses control, taking no time at all to reach orgasm. Gushing so hard it saturates your machine in shiny girlcum.

Yuri gets gently removed from the contraption, you'll clean it later. The second you put the guitar down Yena has a lustful gaze, eyes looking very hungry. "You haven't came."

"Well yeah, the prototype isn’t suited for penises currently–"

"Shut up, you know what I meant. Drop your clothes and come fuck us." She spoke for Yuri, though she seems just as down for it. A threesome with your innovator and her friend? Well that's the best idea since this guitar.