This is the third in a multi-part series about Nicole, her big Brother Stoney, and their loving family. I recommend you read the previous chapters to experience the characters fully, as they grow and their relationships evolve.
*****
Anne stood, transfixed, in the hallway of her family's suburban home, outside the bathroom. The sight that held her amazed attention was her two eldest children, Stoney and Nicole, loudly fucking in the shower. Nicole was leaning against the tiled wall of the enclosure, her ass thrust out behind her. Stoney was energetically driving his cock into her from behind, and they were both clearly reveling in the taboo nature of their coupling, judging from the way they were talking. Nicole saying things like, "You really like fucking your little sister, don't you, Stoney?" and "I am so bad, letting my big brother put his hard cock in my hot pussy."
Anne knew she should be shocked by what she was witnessing, but while she was a bit surprised, her predominant emotion was arousal. Incest was a kink she had picked up from her husband, and to see it happening right in front of her was a huge turn-on, even if it was her own children.
Anne and George enjoyed an active and varied sex life together, filled with roleplaying, toys, and adventures. They were still very much in love, even now, in their mid-forties, and although they had both slept around a lot in college, they had been faithful to each other ever since they married, soon after Anne became pregnant with Stoney. Part of how they kept their sex life fresh was through indulging each other's kinks. Anne had grown up without any brothers, and her father had been much older when she was growing up, so the thought of incest hadn't really grown within her, until she met George. George was obsessed with it, and after he told her in a moment of vulnerability that he had been having sex with his brother, father, and uncle, she understood where it came from. He loved to pretend he was her brother or her son, which she found strange at first, given that he had no sisters, and his mother had died in an auto accident before he was five. But she played along, and soon, incest kink had taken root with her as well. Sometimes, she would even wear a strap-on, and pretend to be his daddy or brother, if he asked for it. Now, the sight of the very real taboo coupling in front of her was more exciting than any of the many games they had played.
She always told herself that pretending, in the safety of their bedroom, that George was her son was harmless fun. But now, watching Stoney drive his sister wild with lust in the shower, she knew she had been fooling herself. Her little boy had grown into a virile man, and she wanted to be the woman on the receiving end of that cock. She wanted to feel his girth stretching the very same pussy that had given him life. She wanted him to know, in his very essence, that his mommy loved him, in every possible way. She wanted, truth be told, to give herself to him, just as his sister was even now begging him: "Take me Stoney! Fill me! Make me yours!"
Ann felt faint for a moment, and she leaned against the doorframe, risking being seen. Her pussy felt hot, and she knew it was probably soaking her panties, making itself ready for the action she was imagining. Her hand massaged her bra-clad breasts. She could feel her nipples, hard and standing tall, even through the business-proper blouse and heavy-fabric bra she wore. Her passion built as she watched the taboo scene play out in front of her, but before she could get close to an orgasm of her own, Nicole cried out in ecstasy and the clasping pulses of her orgasm sent Stoney over the edge as well. Thankfully, they stood like that for a long time, with him still inside his sister, as they whispered things to each other that were too faint for Ann to hear. This gave her time to withdraw down the hallway without giving herself away as they whispered their sweet nothings.
As she crept back down the hall toward the front door, she felt a twinge of guilt at the nasty fantasy she had just let herself indulge in. Playing around with her husband was one thing, she reminded herself. Actually doing something about the fantasy was another level entirely, and she wasn't ready to cross that line. Not yet...
*****
Stoney felt he was in heaven. For the first time, he was fucking his little sister Nicole, something he would have thought impossible just 24 hours before. The hot water of the shower pounded on their skin, lending a comforting warmth to their coupling. There was a slight draft from the open bathroom door, however, which left him peripherally aware when the draft increased momentarily as the front door was opened. So, when he saw movement at the doorway reflected in the polished chrome of the fixtures, he wasn't completely surprised. He didn't stop what he was doing, however: he was so carried away in the moment that he no longer cared if anyone saw him pistoning his cock in his sister's willing pussy. Besides, she was about to cum, and he could sense it. Nicole cried out in joy as Her pussy pulsed with her orgasm, and the sensation sent Stoney over the edge as well. He added his voice to hers, echoing off the bathroom walls "Oh, God, Yes! URRRGH!" Despite having already cum earlier, he produced several massive gouts of sperm, bathing her cervix with the hot ejaculate. As he continued to thrust into her, their combined juices were whipped into a froth, washed away by the warm shower as it dripped out of her, around his shaft.
Their bodies still joined, though moving slower, Stoney leaned forward and whispered in his sister's ear, "Don't look now, but someone is watching us. You aren't the only voyeur in the family, it seems." He guided her head to turn and look at the reflection in the fixtures, disguising the move as turning her head to kiss her.
Nicole whispered back "it must turn you on, because you're still rock hard."
He grinned "I am a bit of a show-off."
She wiggled her ass against him. "The word is exhibitionist," she whispered, while kissing him over her shoulder.
"Screw you!"
Nicole giggled. "You already are!"
"They're gone now", he whispered. "I couldn't tell who it was, could you? I didn't dare turn to look directly at the door."
Their mother's voice called out "Kids! I'm home early! Anyone want to do lunch with me?" followed by the overly-loud slamming of the front door.
"Well," said Nicole, "that answers that." Stoney suppressed a laugh as he withdrew from her, and turned to step out of the shower.
Nicole Called out "We're in the shower, mom! We'll be out in a minute!" Causing Stoney to stop, staring at her aghast.