I must admit that I was getting a rise, as sluggish and slightly painful as it was after my orgasm, out of watching my fiance manhandle her sister into what promised to be another interesting bondage position. She wasn't having much trouble, either. Not only was Tammy exhausted, Tasha topped her by almost 6 inches. At 5'7", Tasha was a big girl, and had started lifting weights over a year ago in a (so far) futile attempt to become stronger than I am. With full hips and busom, a narrow waist, great, firm legs and beautiful features, she was a sex goddess. Her sister, on the other hand, was her complete opposite in everything but her beauty. Slender, firm legs led to narrow hips and small, firm, round ass. Her waist was so small I could probably encircle it with my hands, and even her ribcage was narrow. Her breasts, although not large, looked so on her tiny frame, and pushed out provocatively from whatever she wore. Her face had a look of youth about it--a smooth oval with full, red lips, a delicate nose, large, asian eyes, and a continuously pouty expression. It always amazed me that two such ugly people as their parents could pop out two such gorgeous females. I shook my head with my thoughts as I began gently stroking myself back to hardness. Tasha was done now and was standing back to admire her handiwork. "Nice job," I said, standing up and taking in the full view. Tammy was standing, her ankles spread almost three feet apart by a heavy steel spreader bar which rested on the floor between her feet. Her knees were locked straight by padded black steel cuffs, seperating the line from her calves to her thighs. Her forearms were looped together as close as could be managed behind her back and pulled up, the rope around them tied to yet another convenient overhead beam, forcing her to bend over at her waist, her head slightly lower than her small, firm, round ass, which was lewdly displayed for my enjoyment and, it became apparent to me, her punishment. Tasha had removed the clips I had attached to Tammy's nipples, and now her breasts hung heavy from her chest, her small nipples hard and aching from the blood returning to them. Her long black hair was pulled back and tied around the rope which pulled up her arms, pulling her head back forcefully so that she was looking straight forward, her jaws spread wide by her gag, and her eyes frightened by what was happening to her. "Sit back down, lover boy," Tasha snapped at me as I stood, so I did. "This bitch has to pay for destroying my nice comforter. Stupid slut," she spat, slapping her sister hard on her bare ass. With that she walked over to our closet and stepped inside. Half a minute later she reappeared holding what I affectionately named "the slapper". It was a homemade whip, of sorts. It was made out of a single piece of thin leather about six inches wide and four feet long. The top 10 to 12 inches of the leather had been spliced into three parts and wrapped around a wooden dowel, being tied in a knot at the end and soaked until it shrank around the dowel. "The slapper" was actually one of our favorite toys: it really didn't hurt that much if you were slapped with it (although it did take some time to avoid hitting each other with the edge of the damn thing), but after a few minutes, you were on fire, and each blow was true agony. It didn't leave any lasting marks either, although it did turn flesh to a beautiful shade of red. The great thing about it was that you could custom the level of agony you inflicted by altering the number of blows. <WHAP> the first blow landed on Tammy's upturned ass, her breath whooshing from her nose in surprise and her gorgeous young eyes widening, pleading with me to make her sister stop. Three more blows struck her ass in quick succession, making her whole body jerk in her bondage, making by cock harden even more. Tears began to fill Tammy's eyes as I continued to stroke my cock before her, Tasha laying into the back of her thighs now, the sound of leather on flesh filling the air. Tammy's whole body began to shake and buck in agony as my fiance relentlessly beat her, her ass and thighs a bright crimson, tears coursing down her face to drip onto the slickly polished hardwood floor, ragged screams escaping from around the ball gag to join the wicked sound of leather hitting flesh, creating (for me at least) an incredibly erotic caucophany of sound. "Tasha," I said sharply, noticing she was nowhere near stopping, "don't you think her skin looks a bit yellow?" When we were ungagged, that was our safeword, as well as our call for adventure--the proper name followed by the word yellow. One last <WHAP> and one last agonized scream and my fiance grabbed the end of the strap, "Maybe you're right." She walked around until she was kneeling before her sister, staring straight into her tear-stained eyes, "but don't think I'm finished with you yet," she snarled. "Bring me the jolter," she commanded me, and I whistled out loud. "You really think she can take it?" "Shut up and do it!" she practically screamed at me, gripping her sister's chin in her hand and shaking her head back and forth. I knew from experience that when my fiance got in a mood like this I had two options: either throw her down and rape the shit out of her, which was getting harder the stronger she became, or do what she said. I opted for the latter. "The zapper" was another one of our homemade devices, a car battery mounted on a rather ugly piece of partical board, the wires coming from the poles run through five different resisters, each resister turned on or off by a single switch. We had split the wire into five pair of wires and attached allegator clips to each end, which in themselves were a type of torture. I handed my fiance the zapper and walked behind her sister, enjoying the beautiful sight of her beaten ass. I ran my hands gently over her cheeks, enjoying the soft moans which escaped her lips at the pain from my touch, and the small jerking of her body away from me. My cock was at full mast now, and I slid it between her well-spread thighs, surprised to find her cunt slick and smooth. Tammy was grunting frantically now, her slender body twisting madly back and forth as she watched her sister prepare the zapper, but I ignored her, instead feeling the inside of her thighs, my hands coming away wet with her juices. I slid my foot forward and into a puddle of slickness. I really couldn't believe it. Who would have? The little bitch of my almost sister-in-law was a hardcore masochist--usually the pleasure came only after the beating was done. "In her ass," I heard my fiance say as she attached one of the clips to her hanging nipple, causing her to contort even more in her bonds. I looked dubiously at Tammy's small, pink asshole, nestled lovingly between her reddened, throbbing asscheeks, and reached for the lube. I didn't have an enormous cock, but it wasn't small either, and Tammy had the smallest, tightest asshole I'd ever seen. But hell, it would be worth a try. Tammy began to release small cries from her throat as my fiance began to attach the final three clips to her pussy, one grabbing the flesh just below her clit and one each gripping her inner labia. I knew from my fiance how painful that was (and from some experience myself), but I didn't think Tammy had any idea of what pain she was going to experience when I had my cock up her ass. I pushed one finger, covered with gobs of lube, into her ass, and felt it spasm around my finger, tight even with one narrow digit violating it. Her whole body jerked as Tasha hit the juice, and I knew she was feeling the kick of electricity in her most tender parts. I prepared myself and set my cock up against that small, pink ring of flesh and began to push inward slowly, seein her flesh resisting me as I tried to penetrate her, her flesh spasming with the continuous flow of electricity to her tits and cunt. I slapped her ass hard, my cock a solid steel pole of lust as she screamed into her gag, her ass giving a little. I slapped her ass again, muttering "bitch" under my breath as she howled in agony as her ass began to strech around my cock. My fingers were digging into her hips, leaving bruises as I felt my cockhead slip beyond the ring of her ass, gritting my teeth at the delicious pain it was causing me. Tammy was howling constantly know, great wracking sobs coming from her throat as I violated her virgin ass, Tasha turning up the current, making her thrash about even more. I drove relentlessly down, inch by slow and painful inch, seeming to drag her skin along with my penis. I had never ever been in a hole so tight--only once had Tasha even bound my cock this tight--it was wonderful, wonderful to be fucking this hot teenaged piece of meat who was screaming and sobbing and bucking under my onslaught. It was so good as I slid the last inch in, my hips pressed against her cheeks, my cock buried deep into her ass. If I hadn't come earlier, I would have now, just standing there, the way her rectum was spasming in pain with my penetration and the elecricity coursing through the body. I pulled back slowly, not surprised, even will all the lube, at the thin streak of blood on my cock. I didn't care, though, this bitch was too much, too good. I was going to fuck her until I filled her full of come. I began pushing my cock slowly in, her tightness making it impossible to fuck her any faster, and dragging it out, every inch a fight, every stroke a wonderful agony for me as her rectum continued to spasm around my invading cock. The little bitch was howling and shrieking continuously now as Tasha upped the juice one more notch and I worked in and out of her ass, her young, slender body shaking epileptically as we assaulted her sexual organs. The sound of muffled screaming and squelching and heavy breathing filled the room, along with the heady scent of sex and sweat and lust. I began to feel that familiar tingling, so akin to pain, just below my scrotum, and knew I was going to blast into her soon. My jaw was clenched and my hands were clawed about her hips, practically dragging her off the ground with each inward thrust--I was close, so close. I felt her ass practically squeeze my cock off and I gasped out loud, my come boiling out into her bowels as I felt her whole body tense and liquid splash at my feet, splattering me with her come. My cock was still throbbing as I held onto her, dizzy from my spending, as a steady stream of fluid hit the hardwood floor and bounced up in every direction. With a start I realized she was emptying her bladder and began slapping her ass, loath to remove my cock from her ass but pissed she was pissing on the floor. God, Tasha hasn't cut off the juice, I thought just before Tammy practically leaped off the floor, bonds and all, and her urine stopped in midstream, to be replaced by a huge gush of come as an orgasm wracked my fiance's sister again and again until she hung limp in her bonds, her head hanging heavy against her hair. "Jesus," was all I could say as I pulled out and stepped back, and watched as Tasha unhooked the juice, my cock quickly flagging from one of the best orgasms of my life. Tasha grabbed her sister's hair and gently slapped her face--she had actually blown her lights out. I was still amazed as I staggered off to the bathroom to clean myself up and take a well deserved break. This was Tasha's party, anyway--let her take care of the clean up.