I thought about the demon's proposition. I desired more than anything in this world to become a powerful witch, but was I willing to offer this kind of service in exchange? I looked at the demoness, at her muscular physique and tall stature. She was certainly attractive, not at all what I imagined a demoness to look like. I've had sex with a lot of women who had a similar build, minus the horns, tail, and red skin of course. Maybe this wasn't such a bad deal after all. Besides, I was about to sell my soul to her only a few moments ago so this new agreement could only be an improvement. I made my decision.
"Okay," I said. "I agree to your terms, My Lord. Your power for my sexual service."
The demoness grinned at me. "Perfect," she replied. "Let's get started then."
The demoness pulled aside her loincloth to reveal a large cock. I gasped, surprised that she possessed this set of genitalia. The demoness chuckled, seemingly amused by my apparent assumption, but said nothing. She waited, perhaps for me to show her my worth. I had never had sex with someone with a real cock before, but if it was anything like the toys I used, I had some hope in my abilities. I got to my knees so that her cock hung in front of my face. It was almost the length of my forearm, and it wasn't even hard yet. I decided to begin before I could worry about how big it may grow.
I grasped the heavy cock in my hand, lifted it up and moved my head forward, burying my face in the demoness's balls, licking and sucking them while I felt her cock become hard in my hand. The scent of her cock was overpowering. I pressed my wet tongue against her testicles and moved up, licking her cock along the shaft all the way to the head. It had definitely gotten bigger. I circled the tip of her cock with my tongue while wrapping my lips around it, a little surprised at how nice it tasted. I began to bob my head back and forth along her thick cock, and I could feel it enlarge and become even harder inside my mouth. I managed to take a few inches of her cock in my mouth when the demoness put her hand on the back of my head.
"Mmm…" she moaned. "You're good at this, but it's time for me to take control."
The demoness put her other hand behind my head and began to push my head along her meaty shaft, slowly forcing her cock down my throat. Six inches… eight inches… ten inches! Half of her length was inside my tight throat, using my saliva as lubricant. My throat tightened and I choked and gagged, sending spit out of my mouth and all over her cock. Tears began to build up around my eyes. The demoness pulled her fat cock slowly out of my mouth and I gasped for air as she rested her cock on my face. We had barely even started and there was already a mess everywhere. My spit had dripped down my chin and onto my shirt, and it was all over the demoness's cock. My black lipstick was ruined and my eyeliner was carried by my tears down my cheeks. The demoness smirked at me.
"You'd better not be exhausted already, witch," she said. "Because this is just the beginning."
Before I had time to fully recover, the demoness shoved her cock back down my throat, faster than before. Ten inches… fourteen inches... eighteen inches… twenty whole inches! I had no idea how this was even possible, but her entire cock was suddenly crammed inside my throat! I could barely breathe, and as fun and addicting as her cock was, I began to wonder if I would even survive this. The demoness pulled part of her cock out of my mouth before shoving it back in again all the way to the base. She did this again and again, fucking my face with her massive cock, increasing in speed and brutality. I was choking and gagging uncontrollably on her cock, and spit was going everywhere. I had to grip her legs with my hands to keep myself stable as she violently throat-fucked me. Finally, after a powerful thrust balls deep down my throat, her cock began to pulsate and she shot her warm cum inside my throat, filling me up so that her cum overflowed onto my lips and chin. There was so much cum that it took multiple gulps to swallow. The demoness pulled her spit-covered cock out of my mouth and it hung in front of her, cum still dripping from the tip. I licked up the dripping cum so that none of it was wasted, which made the demoness chuckle.
"I can see you're already addicted to my unholy cock," she said. "Well you'll be happy to hear that I haven't finished with you yet, slut."
The demoness gripped my hair and pulled me quickly to my feet, then bent slightly to kiss my cum-covered mouth. We locked lips and she pushed her tongue inside my mouth, groping one of my tits through my shirt while we made out. I noticed that her tongue felt like it was longer than an ordinary human's tongue. She pulled away, showing that her tongue was really long just like I thought, being at least 6 inches, and she licked up the cum on her lips that she picked up from me. Then the demoness lifted me up and threw me on my back on my bed, crawling up the end of the bed and opening up my legs. She pulled down my soaked panties, flinging them across the room, and the demoness began to dig in.
The feeling of her wet tongue dragging against my vulva, from my vagina to my clitoris, made me quiver a little in anticipation. When her tongue reached my clitoris, it stayed there, gently licking it and kissing it. At the sounds of my soft moans, the demoness took hold of my legs and pulled me into her, burying her face in my pussy as her licks gradually became more rough and aggressive. When my moans became louder, the demoness began to softly bite my clitoris too, and she slipped her middle and index fingers inside my wet, dilated pussy, curling and uncurling the fingers so that they grazed my g-spot at the ceiling of my vaginal wall. I bit my lip but it didn't hide any of my moans which were quickly becoming louder and louder. I could feel myself coming close to orgasm, but right before the point of no return, the demoness stopped.
"M-my Lord?" I inquired, my voice still shaky. The demoness rose slightly, still on her knees, and she moved up the bed so that she was over me.
"You're serving me , remember?" She reminded me. "My pleasure is the goal. Yours is just an inevitability."
The demoness pulled off my shirt and skirt so that most of my body was exposed to her and she dropped her massive cock onto me, its length spanning almost my whole body from my pussy to my head. I had no idea how the hell this thing was going to fit inside me, but before I could voice my concerns, the demoness pushed her cock inside my pussy, venturing deeper and deeper inside me. Her cock was so big that it stretched my vaginal walls and I could see a cock-shaped bulge moving up my body. Every inch of it caressed against my g-spot as it moved. The demoness pushed her cock further and further inside me, way past what I thought I could handle, until the demoness was balls deep. I had no idea how my body was capable of taking her cock this deep, but I didn't give a damn. I just wanted her to keep going.
As though somehow reading my thoughts, the demoness responded by swinging her hips back and thrusting her cock back inside me, hard. Her hands gripped onto my waist as she fucked my pussy. She bent over while she fucked me and her lips latched onto my breast. I could feel her long tongue circle and play with my nipple which somehow enhanced the experience of her fucking my brains out. White cream began to escape my vagina and cling to the demoness's shaft. The demoness wrapped her arms around my body, holding me in place as she fucked me harder. I stretched my arms up in response and clung to her neck while also wrapping my legs around her lower back. The demoness's lips were on my neck now, kissing and sucking my skin as her cock ravaged my pussy. The amount of pleasure was unlike anything I'd ever felt. So much so that my moans turned into howling. Just like before, I could feel myself come closer and closer to orgasm until I crossed the threshold. My legs shook uncontrollably as I climaxed, and it wasn't long before the demoness stopped thrusting and began to climax as well, pumping her thick cum inside my pussy while moaning loudly.
When the demoness stopped cumming, she pulled her long cock out of my pussy, letting the cum flow out, making a huge mess on my bed. The demoness stood up off the bed and stretched her arms up, clearly satisfied by the intense fucking she had just given to me. I was still panting, exhausted and trying to catch my breath when the demoness spoke.
"It's been quite some time since I've had a good whore to fuck," she said. "I think that this arrangement will be beneficial to both of us."
I said up from the bed to reply, still taking deep breaths. "I'm glad I was able to please you, My Lord."
The demoness came and sat on the bed. "Now it's time that I uphold my end of the bargain." She said, moving her head forward and planting her lips on mine. The first kiss between the demoness and I had been aggressive, violent, and full of sexual energy. This kiss was different. It was more gentle and sensual. This was the kind of kiss that I imagined a married couple would share. We kissed for a long time until the demoness pulled away and stood back up again.
"There you go, witch," the demoness said. "I have granted you my powers. The witchcraft you practise will be more potent from now on."
I was so distracted by the kiss that I only just realised the surge of energy that I could feel flowing through me. There was certainly something different, and I felt more powerful than I had before I performed the summoning. I got off the bed and knelt on one knee before the demon to pay my respects.
"Thank you, My Lord." I said, bowing my head. The demon chuckled and walked back to the summoning circle.
"You can thank me by offering your body to me during the next full moon." She replied.
The circle began to glow, and the demoness disappeared from in front of me in a flash of light. That was that, I supposed. I went to pick up the grimoire before realising how much of a mess was made. There was cum and spit all over the floor, my clothes, and on my bed, and there were still globs of cum dripping down my leg from my pussy. I put my filthy clothes in a pile and headed to the bathroom for a nice, hot shower. I would test out my newfound power with the grimoire after I cleaned up.