Ben had experimented with his body since he was just a small boy, and now he carried that same curiosity with him into adulthood. What wondrous pleasures awaited him he could only imagine. Sexually, he had married well. She was a wonderful lover, pleasing him in so many ways. She accepted his adventures with her, yet never fully understood just how badly he needed to be stimulated. Imagination took him places he dared not share with her... he feared her rejection of his dream world. She could be creative, but there was still and air of decency in her sexual play, never really letting go and going beyond the accepted standards.

That's why he experimented when he was alone... without her. Oh, he had talked with her about certain desires, and they even participated in the basics. She had watched him fuck a melon, and she had screwed his ass a couple times with dildos, which he was truly turned on by, and there had been a few mild bouts of S&M, but there was more to him than she knew.

As a young boy, Ben tired of masturbating with his hands and had no luck with girls, being so shy. He had tried one afternoon to mount the family lab, but she would have nothing of it. It was kind of comical as he looked back on it... on his knees, naked with a painfully hard cock jutting up between his legs, balls pulled up tight and swollen as he frantically tried to hold the bitch still. With plaintive eyes, she would look back at him and anticipate his lunges, moving her tail to the side and lining his bulging cock up with her in-heat vagina... dew glistening at the tip of her down turned lips. But she would not hold still as he attempted penetration, and clearly she would not cooperate. Thus ended his youthful attempt at mating with the dogs.

Now, older and wiser, he was experimenting with the dogs again, and he was more in control of himself and his partners. But his tastes had turned from penetrating his partner to being penetrated. This logical step seemed to please all involved, as he was very anal and had been since childhood. He firmly felt that his cock had two heads, the less obvious one buried deeply inside his rectum, which a correctly angled finger or dildo could stimulate to intense orgasms that seemed to come from deep within him, different yet the same as the ones generated by the other head of his cock. These feelings were ones of release and total abandon to the pleasures of his entire body, not just his cock. He liked the feeling of penetration, and the idea of being able to either penetrate or be penetrated, thus having the best of both worlds. And the dogs seemed to like this role reversal as well.

The family pet was a very large lab. Larger than any other he had seen, a cross with some other breed perhaps. One day, with the family away, he had plenty of time to think about the trials of his youth, and as he thought about it, his heart raced, making him light headed at the thought of what he was about to try. How could he do this? But the die was cast and he had to know what the feeling would be, good or bad.

Max, the lab, not used to being in the house, wagged his tail and stood there looking a little lost. Lots of kind words and gentle pats and a little playful wrestling was needed to get him to relax and get accustomed to the inside of the house. Standing there with his cock bursting at the seams, he proceeded to get undressed in front of the lab, and was greeted with a cold nose to his balls as he pulled his underwear down to the floor. Tail swishing about, Max looked excited at this new thing to lick and nuzzle. He was finding out all he could about his master in a way that he related to as a dog. Ben enjoyed this immensely, and turned his body to present his ass to the lab, pulling his cheeks apart to see what kind of response he could elicit from Max. As expected, the nose dived in and took in all of his scent, top to bottom.

Ben closed his eyes and enjoyed having his ass sniffed and the joy was obvious as his cock grew larger as he stood there. Not wanting to leave this new found pleasure, he had to sit down on the edge of the sofa, and present himself to Max, so he led the lab over to the couch and sat down, careful not to sit on Max' anxious muzzle now working over his engorged cock. A gentle lick started him bucking his hips forward to meet the dog's long laps. This sensation was not as good as he had hoped for... definitely not like being sucked by a warm human mouth. But still, his heart pounded at the new sensations and the very nature of this encounter and the wildness of it.

Max was starting to move about back and forth, and a small portion of his pink dog cock was protruding out of his sheath. Ben reached down between his legs, but couldn't reach Max' member, so he knelt down from the sofa and reached under the dog's belly, finding his growing cock. He pulled the sheath back exposing more of his cock, and noticed all the blood vessels and the dark pink color as it filled with blood. Max was not holding as still as his exploration deemed, so he had the dog lay down on the floor, gently rolling him onto his back. Now Max' cock was fully available for Ben to fondle. Applying a little lube to his right hand, Ben used one hand to pull the furry sheath all the way back to Max' balls, while the lubed hand gently stroked the now 8 inches of pointed dog cock. It was similar to his own, yet the head seemed less pronounced and the tip was pointed. There was what could be described as a hard bone running inside Max' cock, which seemed to disappear with more handling and as the dog's erection developed.

Max laid his head back and his eyes took on a glassy stare as his masters handling caused his hips to buck forward, humping an unseen bitch that was only one hand. This sudden fucking movement by Max surprised Ben, and he stopped, fearing the dog would come without mounting him.

Moving onto his hands and knees, Ben called Max to him. Max didn't understand the change and could not figure out what was going on, but liked the exposed asshole being presented to him. Max would not climb onto the back of his master, and as the frustration grew for them both, Ben finally moved next to Max and, with one hand working the dog's cock to a humping action, crawled under Max while working him with his hand. As awkward as this was, it somehow worked and Max was forced onto the back of Ben as Ben simply raised his body up under the dog.

Now Max grasped the hips of Ben with his front paws, and proceeded to thrust his hips forward. Ben reached down between his legs this time and found the five inches of exposed and swollen dog cock dangling behind him and after a few strokes, aimed it at his now lubed and ready ass. Max liked the hand and proceeded to move up the back of Ben, driving his cock tip to the entrance of what he thought was a doggie cunt. The pointed hard bone buried in Max's cock helped push the tip into the rosebud of Ben's ass, and once the heat of both their organs met, the rest was relatively easy. Max stepped up his thrusting, and Ben held onto the base of Max' cock, reveling in the feelings of being penetrated by such a perfect sized cock and with such frenzied force.

Daring to let go with his hand, Ben released the dog's ever growing erection and balanced the weight of them both on his hands and knees. Pushing back against this increasing tempo, he felt the first strike of a bulge that seemed to come from nowhere. Was Max trying to stuff his balls deep inside me, he thought. Looking down between his legs, he got his first glimpse of what he would find out later was the knot that this beast would use to tie up with a female, so that his cock would stay long enough inside his partner to guarantee fertilization.

It was much larger than he could accommodate, being well over 3-1/2" wide, so he reached back to slow the attacking humps Max was feeding him. Grasping the knot in his hand he was instantly excited about the prospects, and thought for a moment he should just go for it. But in that last instance of sanity, he backed off, wanting to save something new for the next time. Gripping hard, trying to simulate a pulsing vagina with his had and now well filled ass, Ben felt the last few deep driving thrusts of Max just before he stiffened and slowed, panting and spasming as his cock rocked with convulsions of pleasure. Ben could feel the rhythmic squirting of dog come deep into his asshole, and the pleasure was immense. His own erection had swelled to dynamic size and now these pulsing waves pounded his prostate, causing first pre-come to ooze from his engorged cock, and finally, with one hand holding to Max' knot, he laid his shoulders down on the floor and reached under himself to grab his own erection, seeping it's own juices onto the floor. A few well deserved stokes and he exploded, body racked with convulsive shock, sending bright light flashes through him mind and tingling quivers from his head to his toes.

Arghhh... a few indiscernible grunts and gentle pleadings finally gave way to thanks as he came down from this unbelievable experience. As his own spasms subsided, he felt the continued rippling of Max as his cocked pumped what could only be quarts of come into him. Finally after about ten more minutes of this relaxed fucking, Max began to go limp and finally, slipped free of Ben's well filled ass.

Ben rolled over onto his back and noticed Max cleaning up his genitals, with the same licks he used to drive Ben's erection onward. Ben stood after a minute to collect his thoughts and when he did, dog juice slipped out past his relaxed sphincter, pooling on the floor between his legs. He had just been really fucked.

A few days later, Ben found that he had been dwelling on the incident with Max ever since it had happened. He had that feeling in the pit of his stomach that only an intense orgasm could relieve. He also found himself at home alone, and after a few minutes of prep work, he called Max into the house.

Max greeted him in the usual manner, with excited tail wagging and crotch sniffing, with Ben returning the favor with some roughhouse play and scratches up and down the powerful body of Max. Quickly taking off his clothes in front of the dog, Ben's erection was sticking straight out from his loins, his balls drawn up tight as Max nuzzled his crotch and started to lick his cock.

Ben knelt down next to Max and reached up under him to find his growing erection. Two inches of pink were sticking out of his sheath, and it was obvious Max was getting the hang of this, sensing what was about to happen. Ben let the dog sniff and lick at his asshole as he gently stroked the dog. A few quick humps by Max and Ben pulled away from him, rolling the dog over onto his back. Only this time, Ben straddled the dog, head to head with his saliva lubed asshole primed to slip onto Max's pink tip. Reaching behind himself with one hand, while briskly rubbing the chest and neck of Max with the other hand, Ben grabbed Max's cock and peeled the furry sheath back down to his ball sack, exposing all of his bright red shining semi-erection.

His blood was rushing through his temples with excitement as he contemplated the pleasure he was about to feel. With trembling hands, he guided the tip to pulsating anus, and with a gentle rocking of his hips back, he slowly impaled himself on Max. After the first few inches were inside his butt, he let go with his hand and pushed downward and back to take the entire 8 inches that had started to enlarge with blood as the tip made its contact with his warm asshole. With the cheeks of his naked ass pushing down on the dog's hips, the humping motion of Max was limited to the basic rolling of the dog's hindquarters off the floor. Max's tail curled to the side and quite moving as Ben reached back between the dog's legs and fondled his balls. Feeling them in there furry sack was a thrill, and prompted Ben to spit some saliva onto his fingers, running them back down past the dog's balls, searching out Max's now spasming asshole.

As Ben gently began to insert his middle finger into the dog's ass, he felt a powerful expansion in his gut, as if someone had stuck a water balloon in his rectum and was pumping it full! It was then that he realized the pulsation's of Max's limited thrusts deep inside his ass were slowing and the knot which he had withheld from his ass the last time he had fucked Max was now buried deep inside him. A fearful shock raced through his brain as the thought about being tied to this huge cock, sitting on top of this lab for god knows how long as he pumped him full of his come.

He quickly tested to see if he could lift his ass off the hot spear shooting up inside him, and the tugging at his inside told him that he was stuck. To pull out now would surely rip him in two, and he didn't want that. After the initial panic flushed, he calmed down and decided that since no one was expected home for the next few hours, he would relax and enjoy the immense pleasures rolling through him like a wave. Some of Max's come had leaked out of his ass when he tried to remove himself, so he reached behind him and scooped some up in his right hand to lube up as he began to stroke his own aching and swollen purple cock. With his left hand he reached back, sitting all of his weight on the dog's loins, and continued to finger fuck Max's ass. Each time he plunged in, the dog's dick plunged and rippled deeper inside him, causing his own cock to spasm as his prostrate got a real workout.

This chain reaction was as though he were fingering his own ass. Riding on the growing wave of spasms, humping and contractions rippling through him, he let out a loud yell as his orgasm rushed out from deep inside his belly. Looking down to watch as the come flew out of his dick, he saw the slight bulge of the dog's cock throbbing out through the front of his lower abdomen. He was a full as he had ever been and could feel the build up of dog come that was now ready to pour out of him. Not noticing a decrease in the swelling of Max's knot, he knew that things must be slowing down for the dog, since he had stopped humping and had a distant gaze in his eyes as he lay there panting.

Rolling forward to nuzzle the dog's neck, Ben felt a large object starting to move out of his bowels, and felt it suddenly give as though he had been stretched to accommodate this now shrinking knot at the base of Max's worn out cock. Suddenly, he was free of Max, and he felt the warm flow of the come as it slipped out of him onto the dog's belly.

His ass was clenching at nothing now and quickly closed shut, stemming off the flow. Leaning over the dog, he nuzzled his neck and told him "Good Boy, Max. You gonna fill me up again, someday?" Max just licked his chops and wagged his tail, waiting for the next adventure.