They do, with just enough time to spare..

James thundered up the stairs, his balls slapping into his thighs as he ran. Lily let go of his right wrist, slapping her hand over her mouth to muffle her excited squealing, and James kept running. With every step, his cock throbbed and lurched more, Lily's pussy twitched and spasmed more, and James kept running. His nipples dragged over his step-sister's back, sending sparks of pure bliss right into his brain, and still James kept running. Finally, Lily kicked open her door, thankfully ajar, and James carried her inside, breathing heavily. He could feel his balls pull the skin of his scrotum tight, inexorably swelling with seed, but to James' relief, he was not cumming yet.

"On the bed, on the bed!" Lily gasped, gesticulating wildly in the direction of her queen sized bed, covers already thrown back.

Her brother carried her over quickly and wrapped one hand over her chest, accidentally grabbing her breast once more, causing Lily to gasp loudly. James then crawled onto the bed on his knees, Lily's free leg dragging over the linen. With his cock still locked tight into his step-sister's snatch by his fat knot, the stimulation almost stopped him short several times, but the fear of getting caught won out, and soon they were lying on Lily's bed, spooning with her fluffy tail pressing into her brother's stomach.

"Oh gaawwd, I can barely..." Lily moaned, desperation clear in her voice, but she shook her head violently and craned her neck to look at James. "Don't move. And not a peep either."

With that, she threw her blanket over herself and James and covered it with a few throw pillows. It was almost unpleasantly hot under the blanket, and James nose was quickly filled with the smell of their mixing fluids. His step-sister's sweltering cunt caressing his rod with its every twitch whittled away at his restraint, too, but James held out. For now.

They heard the sound of Anne's keys in the front door just as Lily added the last throw pillow. James breathed a sigh of relief and felt Lily do the same. Just in time!

Anne's steps moved through the hallway and into the kitchen. James and Lily held their breath, but after their mother fussed around downstairs a bit, no angry stomping could be heard, so they weren't found out. Another sigh of relief, this time in unison. But their relief was short-lived as Anne's steps suddenly moved through the hallway and up the stairs, only briefly stopping on the first step before continuing.

"Lily? Lily, dear, are you home?" Anne suddenly shouted, causing the siblings to flinch, and then to moan as the motion tugged at their respective genitals.

"Y-yes, mom," Lily finally managed to yell back."I'm in my room!"

The steps continued and soon reached Lily's door. James was glad the door to his room eas further along the hallway - the overpowering stench of cum would have made his mother even angrier than the mess in the kitchen. Even so, he held his breath when his mother entered Lily's room.

"Ah, there you are. What are you doing in bed?"

"Just feeling-- nngh... feeling a bit under the weather. Thought I'd get some sleep."

"Hmm, you do look very flushed..." James heard his mother say. "Are you running a fever?"

Lily gasped, her pussy suddenly contracting and squeezing James' dog cock tightly. He suppressed a groan, but felt his hips twitch unvoluntarily, making Lily whimper almost inaudibly. The surpressed sound of arousal finally broke the dam of restraint holding back James lust, and try as he might, the dog morph was unable to keep his hips from bucking into his sister's burning hot snatch.

"N-no, don't!" Lily almost yelled, but her body betrayed her; her hips twisted backwards to give James better access and her pussy sucked him in greedily.

"Excuse me?!" Anne replied, annoyance clear in her voice. James fought to stop himself, but the trip downstairs had eroded most of his selfcontrol and all he could do was keep himself from grabbing Lily's hips and jackhammer away. Squeezing his hands into tight fists, James fought to keep the rest of his body as still as possible.

"U-uh, I mean, don't come in, I-ah! D-don't want you to get sick tooooh!"

"While I appreciate the concern, I don't appreciate the tone, young lady! I will not be spoken to like that in my own house."

"I'm suh-sorry, mom," Lily gasped, fighting to keep her arousal in check. "I'll just--uunngh... sleep a while and feel better!"

"Are you sure? You sound really weird. Are you really alright?" Anne asked with a hint of suspicion creeping into her voice. But even the fear of getting caught did nothing to stop James. He had denied his urges for long enough, and now his libido was taking its due as he delivered short, quick jabs into his sister's drooling cunt.

"Yes!" Lily squealed, her pussy clenching tightly around James' bestial rod, lust terrifyingly clear in her voice. It made James' heart beat even faster - it gave fucking his sister an even better edge, an excitement that hadn't been there before, and he felt the flow of pre from his dick grow stronger. Lily noticed, too, judging by the way her breath caught in her throat.

"What in the world is going on, young lady?! You're obviously not just sick!" The suspicion was gone, replaced by anger, and Anne stepped into the room. James' stomach dropped, but still he found himself unable to stop, Lily's pussy sucking him back in greedily at the end of every stroke.

"Ah-ah-ah-I... My period is--mngh! Super bad, okay?!" Lily shouted, **** to keep her step-mother out of her room. "And I'm--ahnn... m-masturbating to h-help with the cramps!"

"While I'm in the room?!" Anne sounded scandalized, but thankfully, James heard her steps retreat out into the hallway.

"It's... oooh... really bad..." Lily moaned, back arching under the sheet. "And I did... haah... tell you to stay out..."

"That may be, but the two of us will have a long discussion about boundaries, young lady! I'll go running, and when I'm back, you'll better be cleaned up and in the living room."

Finally, Anne left, shutting the door behind her, quick, angry steps stalking down the hallway and the stairs. Now that the coast was clear - or at least clearer - James felt emboldened and increased the length of his strokes as he threw back the covers on top of them, throw pillows flying around the room. He was now using every fraction of an inch the knot still stuck inside his sister allowed him, wrapping one arm around her to play with Lily's boobs.

"Oooh no, buster!" His step-sister's voice, although hushed, sounded somewhere between anger and lust, clenching her abdominal muscles to clamp down on James' turgid rod, its increased sensitivity effectively halting his thrusting. "That was sooooh embarassing! Anne is pissed... mmnnh... you owe me, so I'm taking the lead!"

"I... oooh fuck... I don't mind, just let me blow my load..." James groaned, his cock twitching and lurching against the tight walls of Lily's pussy.

"Roll over. On your back." Lily commanded, and James was only to happy to comply while his step-sister followed the motion until she sat on James' lap, knees at his sides, her yellow-furred tail twitching in anticipation. Her brother's own wagged slowly between his legs, slapping into James' muscular thighs.

"Don't you dare cum until I do," Lily growled, twisting her body to scowl at her step-brother. "Although I'm super-sensitive from before, so maybe you're lucky."

She began gyrating her hips on top of James, making her brother groan in delight as his cock was squeezed tightly as Lily's pussy wrapped itself around his shaft. Lily bit the base of her thumb to keep from moaning out loud, although James had no such reservations as he began fondling his six tits, hands flying from hard nipple to hard nipple as he found himself unable to neglect any one of them for too long.

"Oooh fuck, Lily," he panted, tongue hanging out of his mouth. His voice sounded definitely higher, sultry and sexy, but James didn't care. Nothing mattered except emtpying his pulsating balls. "Your pussy feels amashing!"

Immediately, Lily stopped moving and twisted her upper body around to stare at her step-brother wide-eyed.

"Sshhhh! Do you want Anne to hear?! She's still in the house, dumbass!"

Now it was on James to stare with eyes as big as saucers. All their efforts would be for naught if Anne caught them now! But even so, his arousal did not allow him any rest, and James felt his hips buck into his sister from below almost involuntarily. Lily obviously felt the same, her hips meeting James' own with small slaps of flesh on flesh. They both had fought against insane, until now unknown pleasures for too long, and now that they had a modicum of privacy, nothing could hold them back from finally reaching the lustful peak they had been circling for way too long.

"Oh gaawwd..." Lily's voice was shaky with arousal and need, her tail hitting James stomach with a weak thud every time she slammed down her hips, right between her brother's tits, making the sensitive mounds jiggle slightly. "We nnnh-need to be quiet... at least until she's gone... but--aaanh! It feels so good!"

James had to concur - while his knot prevented any wild motion, the limited range and especially the tugging on his base were enough to reduce him to a groaning mess, lips pressed together tightly to hold in the moans building in his chest. Only that his groans sounded more like whimpers, much like the one Lily had produced when she had set off the current chain of events. Not that James cared with his cock buried in his sister's snatch, her jiggling ass bouncing up and down on his lap.

"Fuck, I can't hold back!" Her voice high-pitched with desperation, Lily increased the speed of her bounces, the wet slaps intensifying. Her juices were flowing down James' balls and thighs, a wet spot spreading under him. Part of the sticky fluid was probably his own pre that had managed to seep around his pulsating knot, but the overall slippery feeling only enhanced the sensations, as did the smell that filled James' nostrils. The heady aroma of sex seemed to fill the room, and James began panting again as it stirred up his arousal even more. But still he had to hold back, at least until his mother had left the house, so he gripped the sheets tightly with both hands, knuckles turning white as he fought to keep his voice down. James' nipples seemed to pulse with his heart beat, six burning points of incredible pleasure rising and falling with his rapid breaths. The relentless **** on his senses left the dog morph near delirious, James' eyes rolling up in his head. This was too much. He wanted to, needed to breed his mate until she couldn't walk anymore, pump her full of his swimmers, but he needed to...

The front door slamming closed was the most beautiful sound James had ever heard, and with a guttural cry that sounded almost like a strangled bark, he slammed his hands onto Lily's hips, making his step-sister yelp loudly, and began rapidly thrust into her from below, tail bouncing up and down wildly.

"Ah-ah-ah-ah yes!" Lily's body was shaking from both her brother's frenzied thrusting and her rapidly building arousal, her tail wagging wildly, slapping into James' arms and whipping the golden fur over his aching nipples, providing yet more stimulation, enough to drive him to the brink of insanity.

"I caahn't--Aaoohnnn, your pushy... sho gooood," James moaned, hips jackhammering upwards into Lily, tongue lolling out of his mouth. He was so close, nuts already gurgling and tightening to release their contents in a torrent of sticky fluid, but he somehow, even through the mind-numbing pleasure racing through him, James remembered that his step-sister wanted to cum just as bad as he did, and Lily was right, he did owe her. So James did the only thing he could think of.

"Ooooh yeeesh, I'm yooor liddle bitsh, pull iiit, fuck me harder," Lily wailed, slurring her words as James' hand wrapped tightly around her twitching tail and began pulling. Her back arched and her pussy began rapidly, powerfully convulsing around his shaft, caressing every inch of James' pointed, knotty prick as it milked his pre right into Lily's womb. "Oh yesh, yesh, I'm--I'm-- aahaaaAAH!"

Legs shaking wildly, Lily convulsed and shuddered on top of James, her bouncing stopped as an incredible orgasm raced through her body. But even though her cunt wasn't sliding up and down on James' cock anymore, the powerful vice grip of his sister's pussy was more than enough to send him careening over the edge.

"Oh fuck, Lily, I'm... oh god.. C-CUMMING!" James entire world shrank down to the sensation of his bestial cock exploding in the depth of Lily's snatch, the orgasm washing through him stronger even than the one he had had when he'd fucked his step-sister in his own room. With every forceful bucking of his hips, another rope of jizz shot into her, James' balls gradually emptying themselves of their sticky contents. Lily squealed and writhed on top of him, the seemingly neverending torrent of spunk prolonging her climax considerably.

After what felt like an eternity of cumming, James' balls were empty, but still his monster twitched and lurched, stirring up his sister's pussy, who collapsed backwards and fell onto James, knocking the air out of him. The sudden weight on his six tits made his cock strain against Lily's walls one last time and then go still, deflating ever so slowly. James wrapped his arms around his sister's waist and breathed in her smell, her head resting on his clavicle. She smelled like oranges and a hint of sweat.