Author's Note: All characters in this series are over 18. If you enjoy the story then please rate and leave a comment, your feedback is appreciated.
"I'll make you as much as you like..."
Dani glared as a dollop of the syrupy white mixture ran down her younger sister, Lily's, chin.
"Please, Lily, how many times do I have to tell you to eat with your mouth closed?"
Ever the dutiful mother, Astrid scooped the mess from Lily's face and popped it in her own mouth.
"Heavens, that really is good!" Astrid exclaimed, "what did you put in here?"
"Spill the beans!"
Dani flushed. How could she begin to explain the events that led up to this creampie? Four weeks of desperately seeking her brother's cum; the complete and utter dissolution of her moral code; accidentally loosing her virginity through a gloryhole - to her father no less - all to win a stupid church bake-off that was now out of her reach.
"I...uhh...sort of made it up...umm...as I went along," Dani stammered, just as a wicked plan began to form in her mind, "but if you want some more then I'll try to ejaculate, I mean, recreate it."
Dani remembered it was only two weeks until Lily's 19th birthday. Her little sister always had the best parties.
"You could be my guinea pig."
"Really?"
"And I could make one for your birthday, if you like?"
"You'd do that for me?" Lily bounced over to Dani and threw her arms around her.
"You're the best big sister ever!"
Dani smiled to herself, picturing her spoilt brat of a sister taking an enormous mouthful of her special creampie in front of all of her friends. Dani knew Lily would gobble the whole pie and that night, as a final birthday gift, she would reveal the mysterious source of the delicious flavour.
"Yes," Dani mused, "revenge really is a dish best served cold."
****
Dani observed reflection in her bedroom mirror, modelling the new pair of black panties she'd bought earlier that day. They were more risqué then her usual style, riding high on her hips in a way that accentuated her figure. She'd always been jealous of her little sisters hourglass body but now she looked at her pert, athletic body in a new light.
The material cupping her pussy tightly was almost see-through. Turning, Dani bent at the hips and watched as the thin strip disappeared between her toned cheeks.
Reaching back, Dani spread her butt and saw her tight arsehole peeking out behind the panties, which were rubbing that delightfully sensitive spot. Dani shivered as she thought back to the times it had been stretched and plundered in the past few weeks.
"Hail Mary, mother of God," Dani whispered to herself as she drove those sinful memories from her mind, "pray for us sinners."
Dani had pledged to end her lustful adventures. Not another man would enter her, in any way, until marriage.
"But that doesn't mean I can't have any fun until then." Dani thought, reaching for the other items from her shopping trip.
Lubing up the unusual toy, Dani felt the thin fabric between her thighs dampening.
"Mike's going to set records when he sees this."
****
MIKE
The jar was on the sink again. Mike thought the whole business would be done and forgotten after the bake-off. Just a moment of madness. Hormones.
But there it was, the glass jar, beside a pair of the sexiest panties Mike had ever seen.
"My sister wore these?" Mike wondered, as he lifted the soaking material to his face.
Dani's scent filled Mike's nose and in that moment he knew all resistance was futile. He was going to fill that jar. He'd fill it all day and all night if it was required of him.
Buzz buzz.
Mike's phone notified him of a picture message from Dani.
Mike nearly wasted his first load in his shorts as he opened the message and saw his butter-wouldn't-melt sister bent over in nothing but her new black panties. Zooming in, Mike was stunned to see, past the almost invisible thong, a thick, transparent plug stretching her arsehole obscenely.
****
Dani nearly missed the knock on her door as she eased the butt plug slowly in and out. It was not as wide as either of the cocks that had taken her arse in the past weeks, but it gave her a pleasant buzz as it slipped past her sphincter and she enjoyed the view as she spread her legs to peer inside herself.
"Who is it?" Dani called as she popped the plug in and drew her bedsheet over herself, moments before the door opened.
"Mike?! You're not supposed to come in here. You have to do...it...alone."
Dani shifted away as Mike sat on the edge of her bed. Her eyes were unwillingly drawn to the outline of his semi-erect penis in his shorts.
"That's just the problem," Mike whispered, "I'm not sure I can."
"Didn't you like what I sent you?"
"I loved it. That's not the issue. Knowing what you're doing with my...deposits...is making me nervous. I think I've got performance anxiety. Your picture almost got me there but then I started overthinking it. I need a distraction."
"I can't help you Mike."
"What if I just... looked?"
"We went too far already."
"I promise I wouldn't touch."
"Promise?"
"I swear."
Dani remembered Lily's smug face as she devoured Dani's bake-off entry.
"Okay," Dani conceded, rolling on to her front, "but I don't want to see."
Dani doubted she could honour her pledge if she saw her brother's magnificent cock. Burying her head in her pillows, she arched her back and raised her arse. Her bedsheets slipped off and Mike was treated to the sight of his sister's expanded back passage.
"Damn, Dani..."
"Just get it over with!" Dani mumbled into her pillow.
Being so exposed for her brother was causing her to thighs to dampen and she feared what she'd do if he continued to speak. If she could just forget he was even there...
But Mike's silence was worse. Now Dani could hear as he dropped his shorts and started stroking over her arse.
"I think it would help if you touched yourself too."
Dani wanted to object, to call the whole thing off, to forget about her brother's delicious cum, once and for all. Instead, she reached between her legs and rubbed her slick pussy. The relief was instant. Dani ran her fingers from her clit to the plug, dipping slightly into her soaked pussy to spread the juice around the glass base that was giving Mike an unobstructed view inside her.
Pulling on the base gently, Dani felt the flared ridge begin to stretch her even wider. Mike groaned in approval.
"Can you do that thing again?"
"What thing?" Dani risked turning her head and saw Mike stroking his throbbing shaft. The tip was inches away from her pussy and, as she thrust the plug back in, she dripped right onto it.
"The thing you do when get really wet. I want to see you squirt."
"These are fresh sheets!"
"Please. I know it'll make me finish."
"It's weird."
"I liked it."
Dani had to admit that it had felt good.
"We're not making a habit of it though." Dani yielded after a moments hesitation.
Dani let go of the plug and moved her fingers back to her pussy. As she did, her hand grazed the Mike's wet cock.
"Mike!"
"You touched me!"
"Just...move it up a litt... Ughhhh..." Dani moaned as two of her fingers easily entered her desperate hole. Curling them, she instantly felt that nub of nerves that would push her towards...
Dani felt a gentle tapping against her plug. Turning again, she saw how close Mike had got to her arsehole; with each stroke of his shaft the tip would knock against the plug and send shivers up her spine.
"I'm not touching you, sis."
Dani felt the pressure building.
"Say that again," she insisted, furiously fingering herself.
"What... sis?"
Dani couldn't explain why but hearing her brother say that word tipped her closer to that precious edge.
"Say...it...again..."
"Fuck, sis. You like this, don't you?" Mike stepped closer and begun to thrust his cock through his sisters cheeks so that his full balls ground into her plug.
"Pleeeaase..." Dani couldn't stop him, the edge was too close.
"You want your brother's cum, don't you?"
"Please...Give it... to me." Dani panted.
Mike was pulling back further now, the ridge of his cock tugging on the base of the plug with each thrust. Dani felt it stretching her as it began to slip out.
"Pleeease..."
Pop!
The plug dropped onto her wet bed and Dani felt the cold air against her gaping hole, for a moment, before Mike's slick cock slipped over it. Back and forth he thrust, catching against her wanting arsehole more with each pass. Dani knew she had to do something, anything, she had to end this before she crumbled.
Reaching blindly, Dani grabbed the plug that had so recently been filling her arsehole and drove it forcefully into her pussy.
"Pleeease cum for me brother!" Dani cried as the wave inside her broke.
Mike froze with his tip pressed against her open arsehole, watching in blissful amazement as Dani's cum was forced around the edge of the plug, spraying wildly in all directions, before her orgasm expelled the plug in a sudden gush of liquid that drenched Mike's thighs.
Shaking wildly, Dani was unable to stop as her trembling arsehole opened around Mike's cock and massaged his massive tip with her vibrations.

"Daniiiii!"
Suddenly Mike was gone. Falling onto her side, Dani watched with glazed eyes as Mike shot load after load into the glass jar.
The siblings were too deep in orgasmic bliss to notice the door to their jack-and-jill bathroom soundlessly close.
****
LILY

Lily slipped into her parents bed.
"Lil?" Her father, Chuck, groaned, half-asleep.
"Couldn't sleep. Busy head."
Chuck let Lily nestle against his body as he wrapped an arm around her. A bad habit they should have stamped out earlier but their youngest always seemed to get her way. With Astrid away on work, Mike was quietly glad of the company.
"Want to talk about it?"
"Nuh-uh."
Lily listened to her father's deepening breath, trying to calm her frazzled mind.
"What the fuck did I just witness?" Lily wondered, a confusing mix of anger, disgust, and, if she was honest, jealousy. Lily had always felt a little left out. Twins. 

Lily nuzzled into her father's arm as he softly snored behind her. It was unusual for them to share the bed alone. Normally Lily would squeeze between her parents and Chuck would turn his back to Lily; now she was enjoying the calming effect of his hold and almost didn't notice the insistent pressure against her thighs.
Deep in sleep, Chuck had inadvertently swelled and slipped from the open flap in his boxer shorts. Lily gasped quietly as she parted her legs and saw her father's impressive penis for the first time.
Lily instinctively closed her legs but only succeeded in trapping the raging member between her pillowy thighs. She tugged her oversized shirt towards her knees, wishing she had worn underwear.
Whatever Chuck was dreaming of, he was enjoying it. Frozen with indecision, Lily noticed that his thing was leaking onto her legs.
