Skele-sexual: Undertale Lemons

Kinky Underfell Sans X Reader

A/N: Warning! This is really hardcore and intense, enjoy at your own risk! ;)

   

      Here, everything makes sense. All your regrets melt away, leaving your mind blissfully numb. Here, you're all San's. And that is all.

      As the chains slither down and coil around your wrists, making loud clangs that rang in your ears, they jerked up towards the ceiling and lifted your body until you were balancing on the balls of your feet. The only thing keeping you in focus was the frantic thrumming of blood pulse in your ears, heating up and racing in anticipation. You were ready, ready for this, ready for him.
     You can barely hear the sound of his erotic voice over the pounding of your heart, fluttering against your own ribs like a caged animal yearning to be set free. Sans shifting through various toys, the chains clattering as he presumably inspects different objects and sets them aside. He didn't need any other tools to make you scream; tonight, he had something else planned for you. You can only listen; your vision has already been stripped away. Underfell has covered your eyes with a blindfold that robs you of your sight completely. It plunges you into absolute darkness, allowing no glimmer of light, forcing you to relinquish any hope of mercy.
Just the sight of the blindfold in Underfell's hand had been enough for your tulip to rain. The helplessness it evokes is dizzying. Right now, strung from the ceiling like a marionette and robbed of one of the most basic senses, left your mind exultant. This is what he wants. To be stripped of anything that binds yourself to the past, to have all the ugly parts of yourself destroyed, and then have Sans baptize him in his desire, transforming both you and him into something new, someone greater.
The footsteps echo in the room, getting louder as Sans approaches your limp body. You struggle to calm your breathing, not wanting him to mistake breathlessness for fear. Here you are fearless. Allowing yourself to fall apart, and reveling in the destruction, for your mind knows Sans will be there to put yourself back together again.
He comes to stand behind you, his proximity making your body shiver. You felt the heat radiating from his soul, and more than anything, you want it to control yours. Burning your own soul with a consuming lust.
(warning, more sexual tension ahead)
Sans trails a finger down your spine, slowly tracing the bumps of your vertebrae, causing a whine to escape your lips and arch your back against him. His silky fingertip elicits sparks of electricity that radiate across your skin.
     "Please," you groans, desperate for more.
      Underfell chuckles. "So needy already. Such a good slut." His docile tone leaving you shivering. The words Sans say don't matter, really. It's the way he says them that drives you wild. He's speaking several octaves lower than normal, in a voice so rough that it almost sounds charred. And more than that, raw energy crackles through every syllable, sparking a fire within your soul. Underfell Sans sounds as if he's hanging on by a thread, his control already threatening to snap. As if all his suppressed power will burst out and pour into you. You may be the one in chains, but your soul ultimately controls Sans.
          He moves over to continue his arousing motions around your hips, a boney digit circulating downwards towards your vaginal lips. He strokes the skin gently, the featherlight touch so reverent you can't help but moan. "Please, please Daddy," you whisper, jerking your hips back to meet his touch.
          Sans nips at your neck, worrying the skin between his teeth as his finger slides up into your clitoral hood. "Patience, little one. First, tell me what you need."  His digit making a lazy circular motion, the teasing touch almost unbearable.
         "I need you," you groan.
         "Need my what? Tell me." Underfell's  teeth dig into your pressure points harder making you gasp at the flickers of pain. Before you can give an answer, San's other hand comes around and rests on your breast, flicking your nipples with his thumb. His red ectodick was erect to it's full extent,  throbbing.
         "Please! Y-your hand! I need you to finger me."
In a silky voice, Underfell whispered into your ear, "Beg."  and teased at your entrance before pulling away when you try to thrust your hips towards his hand. 

     Frustrated, you cry, "Fuck me! Please! I need you so badly!"

      San's fingers immediately wrap around his shaft, sliding up to the head to collect the precome and smear it down the length of his cock. As his hand starts a slow, steady rhythm, he presses his head against your entrance and groans. Deprived of sight, the sensations are almost too strong; every brush of San's digit against your clit, every time his thumb massages the tip of you nipple, every tug on your breast is painfully perfect, causing your eyes to roll up into your head and a constant stream of moans to burst forth. Underfell Sans is at his breaking point. He enters his full length into you with no mercy. You let out a loud cry of pain but it soon turned into immense pleasure. Heavy breaths and groans escaped your lips as Underfell thrusted in and out of your vagina in a satisfying rhythm, moaning with every pound against your body. 

     This was only the beginning, all events leading up to the climax for the both of you. Sans leaned in closer to you, placing a firm grip on your exposed soul, dripping red, making you whimper. He then grabbed his soul and held them close together, the intensity was enough to drive you both mad. Without hesitation he plunged them into each other, melting them into one. Every emotion you both were feeling felt as a whole. The immensity of the pleasure you both felt was indescribable. This was their breaking point. Timing things just right, Sans shoved his cock into your drenching pussy with as much force as he could, making your cherry pop, and you both came with such passion. Your souls pulled away, dripping hot red goo. Underfell unhooked the chains and you fell in his arms panted heavily. He laid you down on his bed and you both collapsed out of breath.