If you asked Cassie now why she started it, she would probably not be able to give you a straight answer; it seemed it was just something that happened of its own accord. It wasn’t as if she didn’t have a great sex life. Indeed, for a fourteen-year-old her sex life was amazing. Her Grampa had been fucking her and licking her puss at least four times a week for several weeks since she went to live with him while her Mom and Dad tried to sort out their marital problems and he gave her at least three orgasms every time. She still got wet when she recalled that first night he came into her room, naked with his cock stuck out hard. She was scared at first when he got on her bed and stripped her panties off. And it hurt like hell, and she bled, when he brusquely opened her legs wide to push his member into her. It was almost as bad the second night he came to her room, but after the third time, when she had her first cock orgasms, Cassie could only wait and pray for his next visit. Other girls her age could only masturbate and fantasise about things like that, but she had it for real. No, it wasn’t for lack of sex at all.

Maybe it was when she found a website showing videos of dogs humping girls that triggered what came next. There was one segment showing a small dog humping a little girl’s leg and squirting, while her Mom filmed it all on her smartphone and told her not to worry and let the dog do it. Then there was another where a big dog tried to mount a teenager in a bikini. It seemed as if the girl was willing to let him hump her until another girl in the room, also in a bikini, intervened and told her not to be so stupid. Squealing with laughter, the girl got out from under, but the dog kept chasing her, trying to pin her again, until she ran from the room. Then there was another showing a small dog humping his owner’s thigh while she, fully dressed, languidly laid on her bed reading a book and letting him do it. And, there was another, very blurry one, where a dog leapt onto a bed where two girls in just panties and bras were fooling around and climbed astride one of them who was lying face down. The other girl encouraged the dog for a while, but then got cold feet thinking things were getting much too hot and pushed the dog away from her friend.

Yes, it was more than likely these shots and others that tipped her over the edge. That, and the heavy yearning feeling in her lower belly she got while watching these things. That same feeling she always had in bed while waiting for Her Grampa to come to her room and fuck her.

It didn’t even enter her mind when Coalie, Grampa’s big, black Labrador cross, sauntered into the living room where she was sat on the floor doing her schoolwork and plonked himself down on his back all over her papers demanding her attention.

“Get off, stupid dog!” she laughed, half amused and half annoyed. She tried pushing Coalie away, but he was far too big and heavy. “Ok dog, I know you’re looking for a tummy rub, so if I give you one, will you go away and let me get on with my work?”

Of course, Coalie didn’t have anything to say. He just lay there looking hopeful.

Cassie started on the dog’s chest like she usually did. She loved the feel of his bristly, black hairs under her palm while she rubbed; and as always, Coalie loved her attentions. Then she moved her hand down past his ribcage to the start of his belly, rubbing all the while. She usually stopped there, but this time, without conscious thought, she moved her hand lower. Down the softer part of him, down towards the hairy sheath hiding his cock and the two big dark balls nestled between his back legs. It was only then that the familiar heavy feeling began; and the moistness in her panties. And it was only when she saw the pink tip of Coalie’s cock begin to emerge from his sheath that she thought, “I wonder if I can get Coalie to hump me like those dogs on the Internet?”

She grabbed one of the dog’s front legs and shook him. “Come on dog, on your feet!”.

Somewhat bewildered by this turn of events, Coalie scrambled up on all four paws and prepared to go away, but Cassie took hold of his collar and pulled him around behind her. “Get on me dog!” she demanded, but the dog did nothing, not understanding what was expected of him. So, Cassie, somewhat exasperated, took hold of the dog’s forelegs and draped them over her shoulders. But still the dog did nothing.

“Jeez, dog! You are kind of stupid, aren’t you?” she muttered affectionately, turning and ruffling his ears. Then she thought, “I wonder what he’ll do if I get up on my hands and knees?” So, she did. Looking over her shoulder, back at the dog, who still seemed somewhat bemused, she murmured softly, “C’mon, Coalie, good boy!”

Coalie slowly came towards her. Thrills started in Cassie’s belly, “Yes, he is going to hump me!” but the dog didn’t climb on her. Instead, slowly swishing his tail from side to side, he lowered his snout towards her butt and pussy. Cassie’s thoughts raced, “OMG! He wants to smell me! Perhaps he wants that first?”

That indeed seemed to be that case, because Cassie soon felt Coalie’s nose pushing at her genital area. She knew she was being very bad, but now sexually beyond redemption, Cassie reached back and pulled her short skirt up around her waist, exposing her pantie clad rear end to the dog. She was not disappointed. She immediately felt the dog pushing his snout between her legs, sniffing deeply. Her legs trembling, she parted her thighs to give him better access. Coalie whined and licked her upper thighs and her pussy and butt hole through her panties. Cassie almost orgasmed there and then.

But then, Coalie mounted her, his forelegs gripping her tightly on her ribs, his weight almost collapsing her. She felt him jerking, hard, fast, rhythmically. “Oh yeah! Good dog! Hump me!” Coalie did not need any encouragement, pushing his groin to her as close as he could get.

Cassie felt a hot, urgent need to cum. Supporting herself on one arm, she reached back and pulled the gusset of her panties to one side. Her fingers found her pussy. “Omg, I am so wet!” Her fingers began to rub, spreading her slippery labia, exploring the opening of her hole, buttering her hot juices up and over her throbbing clit.

It was then that Cassie felt the intruder; a fat, hot, hard, slimy rod pressing against her fingers while she pleasured herself. It was Coalie’s cock, completely out of its sheath. Beside herself with lust she pressed her hand on it and held the cock deep along the folds of her slit, almost sobbing with delight as it slid swiftly over her clit.

But then, by instinct rather than rational thought, Cassie pushed her mound forward a little and pressed the cock up and back. And whoosh! The cock was inside her; thrusting in and in, hard and deep! Cassie orgasmed instantly, falling onto her forearms with her butt still held high in the air. The dog kept thrusting, trying desperately, unsuccessfully, to tie with her. And then he erupted too, pumping what felt to Cassie like pints of hot sperm into her insides. Cassie orgasmed a second time but held her position until she felt Coalie leave her. Then she collapsed face down on the floor. “Thank God I still have my panties on!” she thought as she felt the dog’s sperm begin to leak from her, “I won’t leave a stain on the carpet for Grampa to find!” Nevertheless, she still took some paper tissues from her school bag and shoved them, between her legs inside her panties to soak up the moisture.

Grampa came to Cassie’s room later that night to fuck her, but he let her be when he found her hard asleep.

Two nights later it was Friday. With no school in the morning, Cassie could stay up late. This was a time she really looked forward to. Just her and Grampa, sat in the darkness on the veranda, enjoying the cool night air and listening to the quiet and the night rustling noises as little animals went about their secret businesses in the bushes.

Tonight, Grampa was sat some ways away from her while he smoked and whittled at a chunk of wood he had picked up that afternoon out on the farm. Cassie wished he would stop with the cigarettes, but she also knew that after so many years he would never be able to give up the nicotine. At least he kept some distance from her while he smoked, because he knew she hated the burning tobacco smell.

Coalie banged his way past the fly screen door and lolloped over to sprawl at her feet.

“Hiya, stupid dog” Cassie murmured, pushing at his head and back with her bare feet. “what have you been up to today?”

“Damned dog has been a pain in the butt all day” Grampa said, “chasing all over and upsetting everyone.” By ‘everyone’ Cassie knew Grampa meant the cattle and other livestock on the farm.

Cassie pushed her feet at the dog again, “Hey Coalie, Grampa says you’ve been a pain in the butt all day. Perhaps we should give you a good whupping?”

Maybe it was Cassie’s use of his name, or perhaps it was the affectionate tone of her voice, but anyway, the dog climbed to his feet and came to her, resting his long jaw along her thighs, looking up at her face with his big, dark soulful eyes. “Jeez, you are a big softie!” she whispered rumpling his ears. Then the memory of that part of the dog that was certainly not soft thrusting into her two nights before burst into her mind and she felt a little hot gush of moisture between her legs.

The dog nuzzled at her crotch at the sudden new smell of her. Cassie froze, not knowing what to do. Should she push Coalie away, or should she pretend she didn’t notice anything?

“Damned dog seems mighty interested in your puss, Girl” she heard Grampa say, “why don’t you open up and let him get a good sniff at you?”

“W-what d-do you mean, Grampa?” she stuttered.

“Pull up your dress and open your legs and let him have a good smell at your panties.”

Cassie felt another little gush of moisture leave her, “Omg, thank you, Grampa!” she thought, pretending to reluctantly obey Her Grampa’s bidding, but thrilling inside at the prospect of having the dog nuzzle directly between her legs.

“He’s licking me, Grampa!” Coalie was lapping all over and around her genitals through her panties.

“Let him do it if you like it.”

“I like it, Grampa!”

Grampa got to his feet and came over to get a closer look, “If you’re sure you like it, why not push your panties down and let him really get to you?”

Cassie saw that Her Grampa was kneading his hard cock through his jeans. Her mind raced, “Omg, he wants to see me to do it!” So, she rapidly pushed her panties down, down past her knees to her ankles and opened her thighs wide to let Coalie lick at her bare pussy and butt. “Good Girl!” she heard Her Grampa murmur – it always electrified her when he said that in the special warm tone she knew he reserved just for her - then her first orgasm hit her.

It wasn’t long before Coalie’s long rough tongue lapping at her brought on a second gushing orgasm, and then another, and another; six in all before she couldn’t take any more and had to push the dog’s head away. It was then that she saw Her Grampa had divested himself of his jeans and underpants, and naked from the waist down, he was stroking his long hard cock slowly. A strand precum oozed from his tip. Cassie loved the taste of Her Grampa’s cock and his hot sperm spurting in her mouth, so, wordlessly, she looked up into his eyes and opened her jaws wide.

Grampa nudged Coalie to one side, then, standing astride her legs he gripped her head in both his big hands and drew her firmly towards the stiff shaft, bobbing, hard, demanding, in front of her. “Suck it well, Girl!” she heard Grampa command. She loved him when he dominated her like that, and she willingly took hold of his cock in both hands, marvelling as always at the hot smoothness of it, and captured the big mushroom head in her warm, moist mouth.

Grampa fucked her mouth at the same time as she sucked him. It wasn’t too long before she heard him groan urgently and then felt his hot sperm jetting against the back of her throat. She swallowed all of it, gulping it down to not miss every drop. And, despite so many recent orgasms, that hot, heavy feeling low in her belly began again.

“Goddammit Girl! Take a look at that damned dog, willya?”

Cassie looked and saw Coalie sat on his haunches beside them, panting, his tongue lolling from the corner of his mouth, watching his Master and his Master’s Granddaughter’s antics. Not only that, his cock stood up rigidly from his groin, long, fat and slimy, laced with red veins and with his knot, the size of a small orange, fully developed at its base.

“Poor old bastard!” she heard Her Grampa say, “just think, Girl, he doesn’t have a girl dog to help him out with that thing!” Grampa pointed to the dog’s big, stiff cock, “Such a shame, right?”

Cassie nodded, staring fascinated at Coalie’s genitals. Despite the other evening, it was the first time she had fully seen them.

“How would you like to help him get his rocks off, Girl?”

Cassie acted dumb, “W-what d-d-do y-y-you m-mean, Grampa?” Cassie was already leaking, but more came between her legs at Her Grampa’s suggestion. She didn’t dare say anything about what had happened between her and Coalie two nights before and appear too keen for a repeat.

“How would you like to be poor Coalie’s girlfriend and help him out of that hard-on? He could end up with a bad case of blue balls otherwise.”