The text message from Catriona my Yoga instructor, said: “I am pissed off at you. Watch out. Your ass tonight is mine. My place after 10:00 pm.” My cunt started to quiver. I felt its wetness building and my nipples pebbling. My whole body tingled. Liquid lust flowed in my veins feeding my arousal. Resisting Catriona had been futile since my first yoga class I attended and that she led. There were about twenty or so women attending that day. After our warm-up and stretching exercises Catriona suddenly took off her sweat pants and tank top, revealing her totally naked. “Now ladies, strip naked, NOW!” My heart hammered frantically in my chest when I saw Catriona naked, her unshaved bush between her solid muscular thighs, the dark areolas of her full breasts and even darker nipples brazenly pointing out. I swallowed hard, my breath coming out with short hushed puffs. Our eyes met. Hers were clear sky blue. Did she even know the turmoil she provoked in me? I was entranced by the rise and fall of her breasts or the brief displays of the folds between her thighs that she revealed while assuming new yoga stances. My strength was giving away. A few dark curls of her raven black hair had come loose from her tight pony tail and was clinging to her forehead soaked with perspiration. I could not stand the throbbing of my swollen clit between my legs, demanding insistently orgasmic release. She came to readjust my stance, towering over me her thighs apart straddling me. As she squatted I caught a glimpse above me of her cunt lips slightly apart so inviting to explore their deep dark recess. It was all I could do not to reach with my tongue. She shot me a smile and headed back to the front of the class. Behind her, the full length mirror offered me the sight of her swaying hips and firm ass mounds. When she parted her cheeks bending forward, her legs apart, her tight asshole and the full folds below it stared brazenly at me. I was emotionally drained by the time we hit the shower. I had to work hard to keep my features straight. Suddenly her touch over the bare skin of my shoulder startled me. She was standing naked before me, drying herself, her towel partially covering her breasts, leaving everything else uncovered. I kept thinking “She’s off limits to me. I am married. But the attraction burns so bright it’s impossible to resist.” My skin transformed into gooseflesh. She bent down to retrieve my soap that I dropped and that had slid between her legs. Her face was so close to my open thighs. I could feel the heat of her breath against my curly blond hair hiding my swollen full clit. By then I was sure that if the seepage of my wetness didn’t give away my state of arousal, surely its musty pungent aroma did. “What kind of car do you drive Mrs. Cartwright,” she asked me. “I… family vans … but I would love to try fast cars too sometime,” I blurted before I even realized what I was saying. My voice was hoarse. Sweat began to trickle down my back as I caught the lust shimmering in the clear blue of her eyes. Catriona gazed at me in mock amazement. “Mrs. Cartwright, I never thought you would be interested in fast cars, you being married and all. Don’t you enjoy the ride your husband takes you on in the family van?” “I ... I am sorry… I, “I stutter. “I didn’t mean to …” Catriona’s lips curled into a wicked smile. Instantly I was dizzy. I could see lust in her eyes as she tilted her head slightly and fluttered her eye lashes. “Don’t be sorry” she said in a low throaty voice as she took a few steps towards me and pushed me against the tiled marbled wall with the shower heads. “I only do fast cars. And I would be happy to take you for a ride in mine.” Then she added, “Do you think I didn’t notice you ogling my ass and my breasts from the moment I stripped naked in front of the class?” A half hour before, twenty naked women lathered their glistening skins while making small talk, water running down their body. Now the shower room was deserted. I passed my hand behind her neck and drew her to me. I reached for her lips. Her hands pinched and tortured my nipples as we kissed hard. She started to bite my lower lip before pushing her tongue in my mouth. Soon her right thumb found my clit while two fingers penetrated me, thrusting deeper and deeper. “Please… make me come NOW!” I pleaded; and that was the last rational thought I remember. For an agonizing moment she stopped rubbing my clit, but then she proceeded. I sank into complete oblivion while her tongue drew circles around my erect clit. I screamed as a wave of intense heat overcame me. Catriona grabbed my butt cheeks and spread them, digging her fingers deep in my butt fold. She kissed my inner thighs working her lips towards my waiting cunt. My whole being trembled with renewed lust. I pushed my pussy against her tongue begging her to finish me off. She waited what seemed a lifetime before finally making me come. I watched her head working my clit between my legs as wave after wave of mind-numbing orgasms overtook me. Finally, mercifully she let me be drawn into an indescribable, explosive orgasm as the thunder of my climax destroyed any strength I had left in me. Sex with Catriona has been exhilarating since then, but never without surprises. Tonight I am sure will be no exception. As I ring her doorbell that night after ten, and she lets me in, she asks, “Are you wearing any underwear under your sweats?” “No…” I reply hesitantly. Her eyes don’t leave mine as she pins me against the wall my arms above my head before lifting my top exposing my bare breasts. Her lips brush against mine then press hard against mine before her tongue forces its way in and battles mine for dominance. “No screaming now. And you would do well to keep your hands above your head,” she tells me as she pulls my sweat pants that now lie in a pool somewhere on the floor. A thrilling darkness mixed with arousal overcomes me in anticipation of the disciplining I am about to be meted. Once she secures my hands with TRX cable she ties them to the gym bar for pull-ups she keeps in her home gym. “For all the pain you make me go through watching you naked during my yoga classes…” I have no idea what she will do next. “You deserve punishment, don’t you agree?” I stand there tied up naked, all my intimate parts put on display before a fully clothed Catriona. I feel a vulnerability that just makes my lust flare even more, running hot through my flesh. “Well what shall I do to you?” “Fuck me hard,” I reply. “No. Too easy. The time for me to take your advice is over. Don’t you think? This time…Wait.” Suddenly I remembered her words. “Your ass tonight is mine.” What did she mean? So far during sex she ventured briefly towards my butt, running her fingers along the groove of my ass and swirling a well licked finger around my ass opening... But that was all. Would she kiss it, lick it, finger it? “What’s it going to be? If you don’t tell me …” “Spank me …” My words, coming out strangled are hardly audible. “Oh I will. And tell me why,” she orders. “Because I deserve it” I reply. She presses her right thigh against my slit between my legs. All I want is to grind my clit against the coarse material of her pants. She moves away from me leaving me hot and abandoned. Catriona blindfolds me then spread my thighs wide and runs her riding crop slowly the length of the crack of my ass. “Count out loud.” And then she starts whipping me, heightening my own arousal. Pain roles like thunder through my body making my cunt drizzle juices until finally she stops and unties my hands. I buckle and fall to my knees in a puddle of my own wetness. “Good…” The skin of my ass burns. I am desperate to be realized by an orgasm. All my muscles scream as they contract in agony. She moves behind me and lifts one cheek of my ass to plunge two fingers inside my cunt from behind. My mind frazzles at Catriona’s ruthless rhythm. “I am going to fuck your ass,” she hisses in my ear. I feel her naked flesh against my back. Catriona guides one of her hard nipples along the crack of my ass. I gasp as her nipple explores me deeper and deeper. The gentle probing of my anus with her hardened bud blink in anticipation to grant full access to Catriona. This is no more rough foreplay. It is beyond our simple arrangement, ‘she fucks me and I come.’ It is about breaking boundaries. She slips one arm around me and her fingers soon find my clit. Then, after a few strokes – once or twice -- she focuses again on my ass. Her fingers soaked from my juices lightly draw circles around the very delicate rim of my ass. “I knew now you would enjoy that,” she coos. She has claimed and possessed me like my husband never has. And she . My asshole sucks her finger in as she whispers “bet he never did that to you.” I picture her naked behind me, brooding as she thrusts a pair of fingers in my cunt and two fingers of her other hand up my ass. She leaves a trail of moist lips on my butt cheeks before biting my flesh. She takes me on a frenzy of sweltering desires. Finally a familiar shock rips through me. My muscles tighten around her fingers from front and back as I brace for the final impact. I am breathless as I finally collapse. “What do you think of fast cars now babe?” She asks, kissing me tenderly.