This is a true story. When I was in College I used to date a woman named Martha. She was one of the most incredible women I've ever met, she would do just about anything if it felt good. We used to spend hours in bed screwing in between classes. I introduced her to dildos and various sexual paraphernalia which she learned to enjoy with gusto. One of our favorite activities involved me fucking her in the ass while I pumped her with a huge vibrator in her cunt. One time I worked my fist into her Cunt, it was incredible, I had her on all fours while I pumped my fist in and out of her pussy while fingering her clit with my other hand. She came a half a dozen times or so while screaming for me to stop. It was after one of our major fist fucking sessions that she confided to me that one of her most intense fantasies involved fucking an animal like a dog or maybe something even bigger. She laughed as she reveled her thoughts to me, she said she did not want me to think she was perverted or something. I assured her it was an intense fantasy but it excited me too. And so I made it happen for her. There was a dog that roamed around the campus dorms, basically it was the dorm dog so to speak. It was a huge German Shepard, everyone knew this dog as Bud and it was very friendly. One day after class I brought Bud back to Martha's apartment and left him in the kitchen while I prepared a welcome for Martha that she would never forget. I set up an ottoman in the middle of the floor and attached cloth ties to the legs, another of Marty's fantasy's involves bondage and this would be a great lead in to set her up for Bud. When Marty got back home I wrestled her into the bedroom and started making out with her. In no time I had her jeans off and latched my mouth on to her Clit while I fingered her in to a delirium. Just before she came I told her I wanted to Tie her down to the Ottoman so that She would be on all fours and blindfolded while I made love to her. She liked that idea and agreed to take part. I tied Marty up so that she was on her hands and knees over the Ottoman and blind folded. After I had her secured I started to work on her clit again with me tounge. Marty was was coming in spurts and soaking her loins with her juices. Just as she was peaking again I pulled away. "Where are you going!?" she yelled in frustration as I opened the door and let Bud into the room. "What's going on here?" she asked, I could hear the nervousness in her voice. Without a word I led Bud around behind her. She could hear his feet moving across the floor even though I had put socks on his claws so he wouldn't scratch her. "Don't worry, trust me." I assured her. "Hell no. You're not doing what I think you're doing are you?" she asked half pleading. Marty tried to get up but the ottoman hindered her movements long enough so that I could get to her and hold her down. "Damn you don't, this is embarrasing" she cried. " Shhhh" I said " Relax, I won't ever tell anyone and I won't let him hurt you either." I directed Bud over to Marty's cunt while I held her in place. I put his snout in to her sopping cunt and away he went, it must have been the salty musk of her cunt but he needed no encouragement at all to start working away at her slit. I could see him burrowing his nose into her as he licked frantic- ally at her throbbing loins. I could feel Martha tense up as she came with a loud grunt. I also noticed that Bud's penis was at full staff and sticking straight out of his sheath. It wasn't very thick but it was plenty long and beet red with blood. I pulled him up on to Marty as she struggled to move away. As Bud climed up behind her I helped him move into position putting his penis just inside of Marty's labia. Marty froze. I could tell she was holding her breath. Then with on fierce lunge Bud rammed the whole thing into her. Marty let loose with a "arrgh!" as he caught her by surprise. Then he just clamped on and just hammered away at her like crazy. I could see Martha slowly relaxing as she got into the pounding. "God! Oh God! It's so hot! Ahh...Ahh." Over and over again Bud pistoned in and out of her. Marty was tensing up, and making a rhytmic high pitched "mmmmm!...mmmmm!....mmmmm!" as she came over and over again. Bud was going faster and faster and finally he pushed into her and held still as Marty twitched beneath him making small moaning noises. "He's getting so big!" cried Marty. " It almost hurts. I can still feel him thobbing inside of me. God! It's soo big." I didn't know what she was talking Bud didn't seem at all big to me when he first entered her so I though she was just in some sort of delirium. As I got in behind her to move Bud away but he was buried to the hilt in her! Even as I moved him to the side his dick just swiveled around still lodged in Marty. "Don't! It feels good... Just let him alone.." she said, as I was doing that. And so I left him there as the two of them twitched and Martha moaned softly. When he did pull out of her with a moist pop I was surprised at how much bigger he was in girth and near the base of his penis I could see the hard knobs that I read about in books. It was for real. I untied Marty and let her up. She looked at my kind of uncertainly then giggled as Dog cum poured out of her when she stood up. She worked her way down to my pulsing member and worked me out for the rest of the night. To this day I still remember that session in her room. And as it would prove it would be one of many as Marty really got in to screwing Bud. And it did lead to other, even more incredible things later on. But that's another story.