“Erika, I just don’t – think that-”

“Shut up.”

“But if you would just – listen to what I have to say, I-”

“Shut up.” She jerked her head to the side, one dinner-plate ear flapping with the rush of air across it, and shot a glare over her shoulder at her brother behind him. Max pinched his lips together, held both his paws up in self-defense, and straightened up a bit – but then the motion of the public wave pool rocked both of them together again, and his fortitude immediately faltered. His paws returned to her shoulders, then slid down to her hips again… “You’re the one who got a boner.”

“Yeah, but-”

“It was poking out of one of the legs of your swimsuit. How the fuck does that even happen? How does-”

The rest of her words were lost again underneath the rebound from that wave, chlorinated water splashing against the boundaries of the pool, the rest of the crowd occupying the space still chatting among themselves, laughing… the sensation of her plump, sleek sex sliding back across his shaft where she had wriggled around to bury him inside of her, tugging the material of her own swimsuit to the side to allow him access, pushing back and rocking with her hips until she had worked him in. She had done it slowly at first, carefully so as to avoid anyone noticing – but then one of those rhythmic waves had knocked both of the siblings off-balance and thrust them together, so that they had had to grab on to each for support.

Max gritted his teeth and relaxed again, or at least tried to. He rested one paw along her belly just above the surface of the water, then let the other drop down underneath to where her full canine spade bulged out the front of her suit.

And then he pressed his fingers in against her, pushing her sex back further around him, and felt both of them shiver with the sensation. For a moment Erika’s grip on his arm lightened – but then she just as quickly squeezed him again, and pushed back against him.

“Fucking – awkward position…” she grumbled, halfway bending forward.

Max clenched his jaw to keep from moaning out, hips sliding back, catching in the water, then jerking forward again. The pool water made for probably the worst lube he had ever felt in his life, but it made each extra half-inch so much better by comparison. Once again he buried himself inside of his sister, the leg of his swim shorts wrinkled up against his hip, his body slightly turned, his sheath bunched up.

He pushed that paw down against her again, fingers pushing the waterlogged material in around soft, succulent, arousal-swollen flesh, and took a quick glance around to see if anyone had noticed. “You’re the one who picked it-”

“-and again, you’re the one who got a boner-”

“-and that’s my fault?”

“It’s your dick!”

“Yeah, but-”

Then another wave, this one larger than the last, sweeping both them up off the bottom of the pool, suspending them in swelling water, then lowering them back down – so that the rest of the crowd within the rather overpopulated space could bump and push and nudge against them, each movement making Max tighten up and shiver again, Erika halfway bending forward in what really did look like an awkward position.

She grumbled again. “You’re lucky I got all the fat pussy genes-”

“I would hope so…”

“-so that we can even do this from this angle. It’d be way more awkward if I were facing you full-on-”

“Erika…” Max gritted his teeth, swallowed, and moved his paws down to her hips again, fingers teasing at the waist of her swimsuit. His claws drew little lines through her soaked fur. “Would you – just-”

“Just what? What, Max?” She swung around, dragging him with her, and leaned in towards the nearby edge of the pool. Max gasped, drew back an inch, then plunged in again – and felt her push back against him as she braced herself there, then again, and again. “Want me to make it more obvious? ‘Cause you literally can’t keep it in your pants, when we’re out here, in public?”

“Well I-” His ears flicked, his tail swished beneath the water, his legs shook. He grasped his sister’s hips tightly, thumbs now reaching in beneath her swimsuit, pads poking at the wrinkled pucker of her tailhole nestled just under her tail. “Ah – if you hadn’t – pushed up against me like that-”

“Oh, so it’s my fault? You wanna just tell everyone else here,” and she swung an arm out across the noisy crowd, the movement causing a bit of the water to slop up across the side, “that we’re brother and sister instead of boyfriend and girlfriend like everyone assumes, and – and just… just…”

He gritted his teeth so tight he felt his jaw pop, and flicked his ears back, and wrenched his eyes closed, and trembled where he kept his hips pushed up against his sister’s rear while she bent over the side of the pool. The tension thrumming through her body, the little twitches and clenches, told him that she felt it too – and with the incoming swell of the next wave approaching, the voices of the crowd rising, laughter and shouts peaking, Max hissed between his clenched teeth:

“Eri-”

Then it hit them, and he wrapped his arms tightly around her, and used the motion of the wave to draw back, then thrust forward, pound deep, hold himself there… and spurt, spurt, spurt, each pulse sealing him more firmly inside of her than the last, hips reflexively bumping with each wave of pleasure more intense than the waves rolling through the pool, his knot swelling out right there at the fringe of her limits, barely on the edge of slipping out due to the angle yet still holding tight with each residual clench from her around him, her body responding in turn, her tail swishing against his belly, her rump grinding back to settle him deeper.

Max sighed out, tension holding high, relief spreading through him. “-kaaa….”

“Oh, no.” In front of him she suddenly straightened up, tried to turn to the side – both of them gasped and trembled – then moved as if to put her arm around her brother, but their tie holding tight kept him at that same odd angle. “Oh, God. Oh, fuck, no…”

“Sorry! Sorry, I know, I – I didn’t mean to, it was just – you were – I was-”

“No, not that, dipshit. I don’t care about that.” She reached back with one paw to tug his hips in against her for good measure. “I mean that. Over there.””

Max tried to follow where she nodded. “Uh…”

“Can you see?”

“Well, everything’s a little bit, uh – foggy right now, what with the, uh…”

Another wave, thankfully smaller than the one before, left both siblings shivering and panting. Erika recovered first; Max could not tell whether that was his own throbbing or her pulse that he felt vibrating through his loins. Again and again he looked around at everyone else, heart leaping every time he thought he saw someone looking at them.

Erika’s elbow came in and nudged below his rib, doubling him over – which tugged his knot inside of her, which made him throb and gasp again. It took a good two seconds for his back to relax from the forced arch of the sensation.

“Wh – what?”

“Over there. Look.” She pointed. Max noticed her arm trembled, and when she dropped it back down she gripped the rim of the pool, pulled in a breath, held it, then sighed it out between clenched teeth. So he looked, and…

“Oh God.” Max’s heart dropped again. On instinct he tried to pull away from his sister, swollen sensitive flesh once again pulling tight, and ended up just bending over her instead. She grunted, pushed back against him to try to free herself, and made him shiver and thrust all over again. “Ah – hah – God, what a… sucky…”

Erika halfway covered her muzzle with a paw, huge ears flicking back. “Why couldn’t we just… do this in the locker room or showers like a… normal fucking…”

To Max’s growing nervousness, the point of the siblings’ shared focus had noticed their presence and now wove their way through the crowd to approach. The wild dog straightened up, grimaced through the sensation of his sister’s ongoing rhythmic clenching as her body rode through the downhill of her own orgasm, and made his best attempt at a welcoming wave.

“I can’t believe,” Erika grumbled as their classmate approached, “that you asked her to prom…”

“I can’t believe-” Max felt his smile falter and did his best to steady it. “-she said no.”

“I can.”

“Hey, at least my date didn’t abandon me after asking my sibling to meet me in the bathroom for twenty minutes.”

“Hey, at least I had a date, and-”

Ahead of them Max’s failed prom date paused, perked her ears in response to a muddled call from further back in the crowd, and then looked back to the twins. She raised a paw, mouthed something, pointed over her shoulder, and then hustled back the way she had come.

Erika watched her go. “What the fuck did she say?”

“Beats me. Anyway, I was gonna say – I might not have taken anyone to prom,” and this time his little hip-grind forward was very deliberate, “but I did take someone at prom.”

Erika’s ears flicked again. She scoffed – Max waited for a chuckle – but instead his sister reached back, gripped her rump with both paws, then deliberately spread herself and pushed from inside, so firmly that Max felt the inner muscles of her spade squishing and squeezing up around him. He gasped, shivered, and held onto her tighter, pushing right back in against her movement even as the lips of her sex blossomed out around the root of his knot-

“-I swear to God,” she growled, though her tail wagged against his lower belly, “sometimes I wish – I had teeth in there too, so I – could-”

“You’re gonna – make me-”

His knot forced free from the warm, succulent confines of her insides with a sudden squeeze and tug, though the rest of his shaft remained buried inside. A powerful shudder reverberated through Max’s body, his legs splaying out, his tail hiking up; sweet, delicious warmth sizzled out around him, flowing and fogging like steam in the air, and when he glanced down he saw through the water the thin shimmer of pale yellow streaming out to surround him. Erika once again let her tension out in a sharp grunt, then sighed with relief as her brother finally slipped free – and the cloud of her mark continued to spread out around him, forced out from her pushing, with stray coils of thicker, foggy white swirling as well.

When she spoke her voice was tight, tense, yet relieved; likely she was feeling the effects of the sudden untying much more than he was. “Make you what?” she cooed, and settled her swimsuit back into place around her full spade. Still the wisps of yellow trickled out into the water around them, swelling and stirring at the aftermath of another, yet smaller wave. “Piss? If anyone comes close they’re gonna think you did already. Speaking of which…”

She turned to face him, gave a sly wink, and reached down beneath the surface of the water. Max jumped again when her paw wrapped around his still-hard length, then slid down to the rim of his swollen knot; with her other paw she tugged the leg of his shorts forward and up, and tried to wrangle him back in.

“Put this away. People are starting to stare.”

“Oh, God. They’re not really, are they-?”

So he did… and saw, thankfully, nobody looking at them. Swiftly he plunged his paws into the water to adjust himself, grimacing at the sensation of waterlogged material across his hypersensitive shaft, and tried his best to keep everything contained.

Erika grinned, winked again, and waded through the water away from him.