Just a little note from me.  I am not the original writer of this story.  I found it a few years ago on a now gone website, and thought it was worth sharing with everyone.  If the original author finds it here, please just know how good I thought your work was

Chapter Eight

Jingo never relented on his humping of his mistress, despite her passive and slumbering position. All that he was concerned about was that he had knotted with her. Now all that remained was for him to fill her with his seed as mother nature had intended. His bulgy knot would ensure that she would hold his jism, increasing the chances of impregnation.

Being a dog, he of course had no way of knowing that impregnating his mistress is an impossibility. He was being guided strictly by instinct in this.

For at least ten minutes he kept humping his cock into the still slumbering woman under him. He could beel his balls tighten, a sure sign that he was about to spurt out his cum.

"Ooooh! Wha...what's going on?" Mac finally groaned as she fluttered her eyes open.

The next bang of her head on the cabinet refreshed her memory as to what was happening to her. When her eyes focused and saw Jingo still standing over her, she realized that his cock, and something else, was still stuffed in her pussy. She looked over to the clock and saw that over ten minutes had passed since she had passed out. She reached her arms up weakly to her dog's neck and hugged him tightly.

"Oh god Jingo," she chuckled at him, as he kept up his humping. "Tha... that was the best fuck ever." Mac had falsely assumed that he had finished while she was slumbering and that he had slowed his humping considerably. How wrong she was, and she was about to find that out soon enough.

Then, for no apparent reason, Jingo stood still over her. His cock still imbedded in her cunt. Mac was sure that he must have cum while she had passed out earlier. Then she suddenly felt the scalding heat of his cum shooting to the very depths of her pussy.

"Oh damn!" She exploded into yet another orgasm. "Is this it Jingo? Are you cumming... filling me... with your jism."

Jingo stayed motionless above her as his balls squeezed his seed into his willing bitch. His ballsack tightening with each surge of jism. The dog knew that his knot would keep his fluids trapped within Mac's womb for a good while to maximize his chances of impregnating her.

The dog had been shooting inside of Mac's cunt for over a minute already and still she could feel him shooting as hard as ever into her. She couldn't get over how virile her dog was.

'Are all dogs this horny?' She wondered.

She tried wiggling her ass around to get a full measure of his cock inside of her, but she was still trapped by his body and the cabinet at her head. She would have to settle with just the sensation of his cum filling her belly.

Finally, after what seemed to be forever, Jingo's stream of cum seemed to be slowing its flow. Mac's internal clock told her that the dog had been cumming continuously for over four minutes nonstop. A wide grin spread over her lips as she realized that she would never have to go hunting for dick in night clubs from now on. She might even have to reconsider her relationship with Commander Brumby of the Australian Navy.

They were getting close lately, and he was pushing her towards a greater commitment in their relationship, wanting it to move into the personal rather than professional classification. Now that she's discovered what Jingo could offer, she will have to re-evaluate Brumby's aggressiveness.

When she felt sure that Jingo had finally finished unloading his cum, Mac tried lowering her ass to the floor to rest. Imagine her shocked expression when she found that she couldn't get his still stiff cock out of her pussy.

His knot was keeping her tied to him. And his being a strong dog, was able to keep her suspended in the air despite her effort to lower herself to the floor.

She found the tension on her cunt too painful to bear when she let her body hang under him. She had to get her feet back under her for support and relief. She quickly analyzed her situation and knew that they were locked together for who knows how long. She still hadn't come to the realization that this was quite normal for dogs. Or that his bloated knot would shrink eventually and release her.

"Oh shit Jingo," Mac groaned in relief from the painful experience. "We'... we're stuck. It... it must be that ugly bulge in your cock. Someh... somehow it must have got in, and now... now its too big to get back out. Wha... what am I gonna do boy?"

Mac began weighing her options on how best to resolve her predicament. The only thing that came to mind was to try and reach her cell-phone and call someone to come help her with Jingo's stuck cock. But who could she call without sacrificing her military career. Harm? Bud? Brumby? The Admiral? The Gunny?

No none of these men would be of any help to her in this instance. They were all honorable men and she knew in her heart that they would have no choice but to report what they would see. So Mac started running names of some of the women that she knew. She was discouraged to realize that she knew very few of them. And those that she did know were ex- girlfriends of her colleague Commander Harmon Rabb, except for Lieutenant Harriet Simms and she was married to Bud Roberts.

'What about 911?' She wondered. 'Should I call the civic authorities?'

All this time, Jingo remained motionless like a statue over her impaled body. His cock as hard as when he first got aroused by her sexual scent.

'No, can't risk that either,' Mac conceded.

She decided to wait a bit longer in the hopes that she could work her cunt off of his raging hardon.

Fifteen minutes had passed since she was confronted by her being tied to her dog's cock. This little respite was what Jingo needed for the second round. He began humping his hips to and fro, dragging the helplessly tied woman along for the ride.

Mac couldn't believe that he was ready to fuck her cunt again so soon. All she could do was lift her hands up over her head to protect it from the hard cabinet that she was pounded against previously.

Sure enough, Jingo's ass was humping into her at a rapid pace. If she could have been watching instead of being fucked, she would have thought his as was a blur. He again lowered his large head to her tits and began suckling on them alternately like an overgrown puppy.

"Ungh! Ungh! Ungh! Oh Jingo! Ungh!" Mac grunted with each thrust.

This time Mac managed to remain conscious through it all. She had three more orgasm before the dog's balls tightened in their scrotum.

She exploded in a fourth and more powerful climax when she again experienced the surge of cum being shot into her. Mac couldn't figure out how her cunt could hold so much cum that had been emptied in it in such a short time.

Once done Mac collapsed in climactic exhaustion, having worked harder for her breath than any workout she had ever done in her life. She couldn't remember being so satisfied by any man, or beast. The memory of the Wiccan's Ram flooded her mind and she decided that Jingo was even better than that.