Gosh he's a big fucker, thought Sara, as she watched her dad's Great Dane Shadow come bounding up the steps. She still wasn't used to such huge dogs.

Dad had bought him after he moved out of the house, and though she liked him, Sara was always a little nervous about being near such a gigantic beast. No matter how friendly he was, she could never get over the feeling that something that big had to be a little uncontrollable. At the sound of his name, he loped towards her, landing half in her lap and licking her face with his wet tongue. Laughing, she pushed him off and hoisted herself off of the porch steps.

Sara was 18. Her parents had split up a year earlier, and these summer visits to dad's house were not the highlight of her life. She knew that he loved her, but it seemed like he could never bring himself to show it.

Consequently, many dinners were spent in silence, and not much was said besides the usual chit-chat. She missed her friends back home; dad lived up in the mountains, with only a handful of neighbors, and things could get pretty lonely. Taking the monster dog for walks in the woods became her favorite pastime; the first time dad had asked her to she hadn't wanted to, but Shadow was always well-behaved and she gradually grew to enjoy them.

After a time, he became the best friend she had.

She took him out one morning to her favorite place in the woods, a little clearing by a creek where she could swim. The sun was already beating down, but the mountain creek-water was still too cold for swimming. Disappointed, Sara lied down in the dry grass, watching Shadow as he sniffed around the clearing. She loved watching him. She still couldn't believe how big he was,and beautiful; he stood nearly as high as her waist, and his glossy coat couldn't hide the taut muscles underneath. His loping was so graceful, his body so smooth. He trotted over in her direction as she called his name, a huge doggy grin on his face. Laying down next to her, he nuzzled her hand until she began petting him. Sara knew that he liked to have his chest scratched; she put her hand down between his forelegs, and he rolled over on his back next to her, paws up, panting with enjoyment. His penis hung to one side between his legs; Sara had been trying to work up the courage to touch it for the whole summer, but hadn't found the nerve. Her sex fantasies had been about Shadow since July, but she had always been too scared and confused to even think about acting them out. She could not deny to herself, however, that she had a crush on him. I'm crazy, she told herself. How could anyone ever fall in love with a dog? She had heard about animal sex before; but people couldn't really do it with the animals, did they? She wasn't sure. But that day, after seeing how handsome he looked in the grass, she reached the breaking point. Whether it would work or not, she didn't know; but she finally decided that she was willing to try.

I'm going to do it right now, Sara decided. She knew that she loved Shadow and had sexual attractions to him, weather he was a dog or not. Gently, she slid her hand around Shadow's hot, heavy penis, making him whine and squirm under her touch. Immediately, she could feel the knot starting underneath his skin; the thought of it being inside her gave her goose bumps. She lied down next to him, snuggling against his huge, hot body. Pulling his head towards her, she kissed him as well as she could, even forcing her tongue into his dog-breath tasting mouth. Her hands slid over his body, caressing him; she loved feeling his hard, taut muscles under his smooth fur. Her breasts, swollen and tender, fell against him as she slid her t-shirt over her head. She kissed him again, sliding one hand down his belly, and, upon grasping his penis was pleased to feel that he had grown noticeably.

Giggling, she slid down him and rubbed her breasts against it, their soft white skin turning pink against Shadow's hot, heavy shaft.

He's probably been waiting for this all summer, Sara thought, as she slid Shadow's sheath down the length of his cock. It was huge, much bigger than she had ever expected; she didn't know that anything had a cock that big.

Shadow had been enthusiastically humping her hand; when she let go of him, he jumped up and put his forelegs over her shoulders, jabbing his erection into her back. Sara giggled, trying to push him off for a moment so she could get her shorts unzipped. They finally came off, and her panties with them; naked, she grabbed Shadow's cock with both hands, which by now had extended to an unbelievable length and had a gigantic red knot at the base.

Clear, watery semen dribbled out of the tip of the dog's monstrous organ as he began humping Sara's hands again, coming out in little squirts with each thrust he made against her palms. Her belly wet with semen, both hands wrapped around Shadow's stiff cock, Sara couldn't believe that she had waited so long. Twisting herself under the grasp of the dog's forelegs, she lowered herself onto all fours below him, and gave a little gasp of pain and pleasure as he wrapped his forelegs around her waist and his enormous cock penetrated her. Shadow yelped, arching his back upwards and pulling his body higher onto Sara. Panting wildly, he began humping himself into her with a frenzy, thrusting deeper into her vagina and wriggling his stiff penis upwards until the base of his knot pressed against her lips. Eyes closed, Sara moaned with pleasure as Shadow's penis penetrated her deeper and deeper; pushing backwards against his powerful thrusts, she knew without a doubt that this was the best sex she had ever had. She felt his knot pressing against her, hard; she pushed against it as hard as she could, and cried out in pain and excitement as it stretched the lips of her vagina open and slid inside her.

Sara couldn't control the moans that were escaping her; Shadow was giving her pleasure that she had never experienced before. Tingles of electricity shot up her spine each time Shadow shifted himself within her, and she could feel him growing rapidly. The pain of his knot within her was worsening, little by little, but she was enjoying it immensely just the same. An orgasm was building within her, shivers of ecstasy overtaking her body, hardening her nipples, flushing her face, and finally coming to a head and exploding within her like a blossoming flower. Waves of pleasure shook her whole body, forcing her to cry out again and again as each one did it's work. Orgasmic bliss wracked her body with intense pleasure. With each thrust he made, Shadow sent a new sensation throughout her body. Suddenly he yelped loudly, pushing himself against her body, and Sara felt his penis throb mightily and knew instinctively that he loosed his sperm into her.

His thrusting ceased; he licked her back, gently, as if in appreciation, and then dismounted from her. Sara went from disappointment that it was over to alarm, because his cock was still stuck inside; but he didn't seem to mind, simply stepping over it and standing behind her with his ass against hers..

Sara looked underneath her, between her legs, and gasped when she saw how his cock was pulled out between his own legs, backwards. She couldn't believe that he could be comfortable, but she looked up at him and he seemed to be totally overtaken by sexual bliss. Her orgasm was over, but Sara was content to stand with him as long as was needed; feeling him hot and hard within her was a most wonderful sensation. Closing her eyes, she almost imagined that she could feel Samson's gigantic penis throbbing within her; the thought of his gigantic cock spurting thick and white into her made her body shiver with excitement. Shadow, his face a mask of happiness and pleasure, rocked slowly back and forth against Sara as his semen continued to trickle from the tip of his penis into her warm, young body.

They stood for at least ten minutes; Sara had started to wonder just how long it was going to last when she felt Shadow shrinking. Losing erection rapidly, he stepped away from her and popped his semi-flaccid organ out of her with a slight jerk. Sara watched him as he cleaned himself with his tongue, his cock slowly retracting into his body until it was nothing but another fold of soft skin. Still naked, she knelt down in front of him; he licked her face as she stroked his head and ears. "Good boy!", she whispered to him. She stood, wiped away a trickle of semen that ran down her thigh, and pulled her clothes back over her body. Together, they walked back in the direction of the house.