"Oh, is it a pool party?" Serafall turned around as her magical girl costume changed to that of a beach girl.
A two-piece swimsuit and a straw hat, even though there was no sun in the room. She noticed, and the hat disappeared. Altairs felt a little disappointed.
"Something like that. Sona offered to wash me." Altair detected no murderous intent on Serafall's part, but instead found traces of lust adorning her aura.
"Onee-sama! Don't come in!" Sona reacted too late. Serafall jumped in, splashing water everywhere.
It was dark down in the water, so it wasn't entirely clear how Altair and Sona were connected. Still, even so, given their position, it wouldn't be difficult for a voyeuristic observer to realize what they were doing.
Serafall said nothing as she came out of the water, lifting her head and leaving a trail of water behind her.
"Ah, So-tan, why are you so close to Altair?" Serafall asked with a hint of innocence, an innocence that only a fool would believe.
Sona became so nervous that she ended up turning around, her pussy still impaled on Altair's cock, which hadn't changed, and that rotation gave her intense pleasure. Sona watched Serafall's face flush before the older woman turned away. For a moment, she was speechless before feeling Altair's hand caressing her chest.
Her bare chest.
Her bare chest was being caressed in front of her older sister.
Sona didn't have time to make a vague excuse before closing her eyes when she saw that Serafall had taken off her bikini top, leaving her bare breasts floating on the water.
"Onee-Sama!" Sona repeated what seemed to be her favorite word as she covered Altair's eyes. Part of her felt inferior as she felt the boy's cock harden further when Serafall turned around.
"What?" the Maou asked, confused, a pout adorning her face. "Did I get it wrong? Wasn't this a nudist pool party?" she asked as she threw the bottom of her swimsuit in the direction of the two lovers.
"It's not nudism," Sona denied immediately. "It's... Damn it!" she felt fingers squeeze her clitoris.
"So-tan just swore, oh! She's so bad!" Serafall pulled a camera out from somewhere as she took a picture of Sona's stunned face.
Sona didn't know whether to cover her face or her chest and ended up with her hands moving from one side to the other, without completely covering either. The photos ended up capturing both of them.
"Delete that, Onee-sama!" Sona pleaded.
"Ah... but So-tan is so adorable, don't you think, Alti-chan?" Serafall moved to Altair's side in a second.
If it was obvious enough what they were doing before, at that moment, there was no way Serafall wouldn't notice. Luckily for Sona, Serafall showed the photos to Altair, seeming too mesmerized to see what was going on around her.
"She really looks cute with that expression. If you stand in front of her, you'll see that she has similar expressions," Altair said. Sona didn't react until she felt the man grab her waist. She felt his penis withdraw a few inches before filling her again.
Serafall was right in front of her, as if she were a professional photographer.
"Waa! Alti-chan, you were right, keep going, I want to take more photos," Serafall said as she moved from side to side, her breasts bouncing with each movement.
Sona felt her crotch getting hot from the friction, a little pain in the area, but nothing compared to the embarrassment she felt at that moment.
"Stop, Serafall!" she yelled at her sister, but she never said a word to Altair. She could feel the powerful thrusts hitting her butt as the boy enjoyed her body.
"Don't you love me anymore, So-tan?" Serafall said with feigned sadness.
"No, but he's fucking me in front of you!" Sona explained exasperatedly, with no desire to cause her sister any harm.
"He's what?"
"He's tickling me!" Sona corrected her mistake.
"Oh, I remember you're very ticklish on your feet, heh heh," Sona opened her eyes in horror when she felt a stream of water drag her own foot to the surface. Serafall's hand took it and began to tickle her.
"No, Onee-sama, no," she begged.
Serafall stuck out her pink tongue and ran it across the sole of her foot.
Sona felt even Altair's thrusts pause for a second as they both processed their sister's actions.
"Serafall," Altair said in a flat voice.
"Yes?" she asked, unsure of what he meant.
Altair gave her a thumbs up; he had felt Sona tense up when Serafall started licking her feet. Serafall returned the thumbs up and began running her tongue over Sona's feet, all in the name of tickling her.
Sona surrendered to the degeneration; she couldn't even win against the temptation that was Altair. When her sister entered, she expected him to stop or for herself to stop him, but she didn't.
Now all she could do was watch as both horrible devils used her body, her sister seeking to annoy her and Altair seeking to unload his DNA inside her.
She stopped complaining and devoted herself to feeling, to remembering, to overcoming herself.
For a moment, she felt her body floating. It wasn't just the water; it was Altair's cock entering deep inside her. Sona didn't know her vagina was so deep, but Altair filled it completely.
Her sister was worshiping her toes, although she no longer tickled her with her tongue, she licked like a puppy savoring the remains of meat on a bone.
Having someone suck her feet was... pretty good. She would never admit it out loud.
Soon, a third sensation came over her; she felt Altair's fingers making their way into her anus. Sona would have protested and complained, but not this time. The battle was already lost; it was best to learn from it by experiencing defeat to the fullest.
"Put it in harder!" she found herself saying, drunk with sensation.
"So-tan?" Her sister's confused voice stopped all the obscenities she wanted to say.
'Nee-sama doesn't know anything,' she thought with a bit of guilt, as she had taken Serafall's interaction as sexual stimulation.
Altair didn't care about her guilt; he penetrated her harder and faster, so much so that the ripples in the water began to cause it to spill out of the Jacuzzi.
"The tickling is harsh, So-tan?" Serafall asked worriedly.
"Yes, it's... too much... too strong, I think I'm going to pee myself, nee-sama, please," Sona felt the same sensation as minutes before.
He should stop, tell his sister to get out of the Jacuzzi. But he didn't.
Instead, he felt the knot in his lower abdomen tighten, and again he unleashed himself like a fountain. She felt Altair grow in size inside her.
Her legs lifted her like a spring, and she jumped so high that her pussy was out of the water right in front of Serafall's face. She felt embarrassed when, for a second, she saw her sister's eyes open wide. She felt even more ashamed when she came right in front of her face.
"Forgive me, Onee-sama."
—-------------------------
Serafall looked at her sister's pussy, reddened and open, a whitish liquid inside, spilling out. Then she felt a wave of water hit her face. It wasn't normal water, she knew as soon as she smelled it, it was Sona.
'A squirt?' Serafall felt proud of her little sister. Sona fainted from exhaustion or the intensity of her orgasm.
Under the water, she watched Altair's cock twitch as he shot load after load of semen. Serafall approached and helped him, her hand wrapped around his shaft. Seeing how thick it was, she understood why Sona had had such difficulty trying to maintain control in front of her.
But Serafall knew what they were doing from the moment she entered the mansion. She still remembered when Altair let her smell his fingers impregnated with the sweet scent of So-tan.
Her firm, though inexperienced, hand milked Altair's cock as if it were a cow's udder. When the cock stopped moving, she looked at the face of the man who had deflowered her sister.
Serafall jumped out of the water in one leap and dried her body, except for her face. She didn't want to waste the fruits of her sister's labor.
"Take care of So-tan!" she entrusted her little sister to Altair before teleporting out of the mansion.
She knew that if she continued to look at the naked body of the adorable So-tan, she would not be able to control herself.