Girlfriend's Plotting

Kristen quietly tiptoed up the steps, planning to surprise her brother. She had come home from school for winter break a few hours early due to lack of traffic, and figured she'd capitalize on the opportunity, if he was even home that is.

Up she went. One step at a time, careful to avoid that one spot that creaked really loudly. "All this better be worth it," she mumbled to herself, "I don't even know if he's home."

Throughout the years her and Mark and always gotten along quite well. When she went away to college last fall, they had kept in touch. They even told each other personal things. Mark knew about the boy she had been sortof dating sortof sleeping with, which her parents didn't. At nineteen, she had only slept with two men, but together her and her current on-again off-again boyfriend Billy had done massive amounts of experimenting, most of which she had told Mark.

Kristen began to think that maybe she told him too much, but it did go both ways, mostly. She hadn't told him everything, and presumably neither had he. She did know, however, that he had been dating some girl since last fall, right down to the night he lost his virginity. Although she had yet to meet the girl, Mark insisted that she was super cute and Kristen would love her.

Quietly, she passed the top step, and then planted her feet on the hallway floor. She continued down the hall, and noticed that the door to Mark's room was open. She was about to rush in, scream, and demand a hug, but instead stopped dead in her tracks, right in the middle of the doorway. Luckily, her surprised had kept her from audibly gasping.

What she saw she could not take her eyes off of.

Mark was sitting in his desk chair .... and some really hot naked girl was on her knees blowing him.

Kristen was unsure of what to do. She thought she should probably say something, or leave, but instead kept watching. Neither of them had seen her yet. To keep it that way, she stealthily backed up a few feet and peaked her head around the doorframe. The sight was turning her on, and she consciously moved her hand down her jeans and began fingering her slit.

"That has to be Katie," she thought, "Damn she's hot!" Then she heard something that surprised her even more.

"Oh, Kristy," came Mark's low guttural moan. Mark moaned, keeping his eyes on his girlfriend's head which was bobbing up and down on his cock. Katie really enjoyed sucking him off, and he never refused.

"Yea, you like that don't you?" the girl finally removed her mouth form his penis to speak. "Pretending I'm your sister. You wish this was your sister's mouth don't you? And your sister's tongue?" As she said this, she licked up his shaft and swirled the tip of her tongue around the head of his dick. "You wanna cum in your sister's mouth again?" Everything she said was so lustfully done. "Or maybe you want her panties?"

Kristen was furiously fingerfucking herself by now. Apparently her brother had been fantasizing about her ... with his girlfriend, and she was complacent with the whole thing. It was quite flattering. But confusing. She wondered how they had gotten to this point, and why it didn't bother Katie that Mark had been calling her a different name. No matter. She turned back to watch the action, while running a finger along her swollen clit.

Katie was now standing behind Mark, jacking him off with her hand, and Mark was holding a pair of pink panties that Kristen recognized as a spare pair she kept in her room at home. One of her favorites, actually.

Mark was getting close, and they all knew it. He let his head roll back and closed his eyes. Katie did her best to direct his dick so the semen shot into the panties.

"Kristy..." he whispered. "Yea, cum for your sister," was the response from his girlfriend.

Not wanting to get caught, Kristen quietly worked her way back downstairs, got back in her car, and drove around for a while. "Next time I think I'll ring the bell," she said to herself.

The next afternoon, Kristen was unpacking and cleaning up in her room. She was dressed casually, in a pair of sweats and a loose t-shirt, but still looked very sexy. A knock on her door. "C'mon in."

"Hey, Kris, just wanted to know what you wanted to do for dinner tonight -- Katie and I were thinking to get some pizza or something." They only lived with their dad, and he was out of town, wouldn't be back for a few days.

"Cool, pizza sounds great, count me in."

"Okay, I'll letcha know when its here." Before he left, Kristen spoke again to get his attention. "So I finally get to meet Katie tonight, eh?" She had not made any mention of the incident from yesterday.

"Oh, yea, you're gonna love her, she's so cute."

With that, he left, and Kristen continued unpacking, but not before looking him up and down as he walked away with a strange grin on her face. Sweaty, she decided to take a shower. When she came back, she need to find some clothes. For some reason, she looked into the dirty clothes hamper, and that's when she noticed the pink panties.

"He must've slipped it in with the rest of my dirty clothes hoping I wouldn't notice," she thought aloud. She picked them up and held them. It was obvious they still had her brother's dried cum in them from yesterday, and who knows how many other days maybe. Suddenly, an evil grin appeared on her face.

An hour later, her brother walked in the front door with his girlfriend. Kristen had spent the time alone laying on the couch. She was dressed in that infamous pair of pink panties, which felt so sexy to be in, and a black tank top, with no bra, and barefoot, without even socks

Mark introduced the two of them to each other. Kris stood up, and instead of shaking her hand, gave her a hug, pressing into her and softly caressing her back. "Its so good to finally meet you." Neither Mark nor Katie seemed to notice the panties, or if they did, showed no sign of it.

They talked for a while, ate some pizza, had a good time hanging out. A few hours later, they were all in the living room watching some movie on cable. Kristen lay across the smaller couch while the couple sat on the larger, Katie's head leaning on Mark's shoulder and a blanket covering them.

There were a few nude and sex scenes in the movie, and Kristen was starting to get aroused. By now the channel just became downright porn. She wanted to put a finger down her cum-filled panties, but wasn't sure if it was a good time. That's when she looked over to the other couch.

Mark had his eyes closed, and Katie's face was nowhere to be seen, but underneath the blanket was something moving up and down. Katie's head? She was giving him a blowjob right in front of her!

Well, nothing to lose now. She plunged her hand down and inserted two fingers inside herself, never taking her eyes off the action. Surprisingly, even though it had only been a few minutes, she was close to cumming. Would she let herself have an orgasm right here in front of her brother and his girlfriend? She didn't know, but she need release, and soon.

Then she momentarily shifted her eyes upward, toward Mark's face. His eyes were now open. He was looking right at her. Their eyes locked, a piercing, lustful glare shared between them. No words spoken.

Mark tossed the blanket aside completely. Everything was out in the open now, no going back.

Katie noticed the blanket gone, and looked up into Mark's eyes. She followed his gaze and turned around to see Kristen. Their two sets of eyes locked now, but Kristen never missed a beat.

Katie's reaction: she smiled widely, a devilish grin really. She knew how much Mark must be enjoying watching his sister masturbate. Standing up, she removed her top, then her bra. Then she knelt back down on the ground, and went back to sucking his cock.

At the same time, Kristen had taken off her tank top, her full breasts open for her brother to look at while his dick was in his girlfriend's mouth.

Inserting a finger back into her pussy, she circled and flicked her own clit, moaning loudly. Any second now. "Ooooh, Mark...." she practically screamed. "Aaaahh."

Seeing his sister orgasm was more than he could handle. Mark groaned and spurted his seed into Katie's willing mouth, waiting to take it all.

Katie looked up, sperm still in her mouth, and noticed the brother and sister looking at each other in post-orgasmic bliss. She decided to take it to the next level. Moving over toward Kristy, she grabbed her hand and pulled her to a standing position. She caressed her face, and leaned in, giving her a deep, passionate kiss. Kristy opened her mouth immediately, wantonly. She could taste Mark's semen on Katie's tongue. Together they shared it.

Once they broke the kiss, they both swallowed. Kristy blushed, and lowered her head in embarrassment, avoiding looking at Katie. She had just swallowed her brother's sperm, taking it from his girlfriend's mouth.

"That was the hottest thing I have ever seen." They had both momentarily forgotten about Mark. He sat there naked staring back and forth at the two of them.

Katie moved her hand to Kristen's chin, directed her upward, and kissed her again, lightly. She began softly kissing the other girl's neck. She moved up to her earlobe, licking it, and pushing her tongue into her ear. She whispered, "Let's give him a good show. He loves you, ya know."

This made Kristen's heart jump, to know that her brother really loved her. Not loved her the way he loved Katie; at least she still didn't think so. Loved her like a close sister. She loved him too, as a brother. This .... this was just pure lust, sexual attraction in its rawest form. "Who cares if they share some genetic material?" she thought. "We're both attractive young people with healthy sexual appetites."

She decided Katie was right. Let's give him a show. She moved her hands up to touch and fondle the younger girl's breasts, and simultaneously started kissing her neck too. Then she dropped a hand down and unzipped Katie's jeans, which were still on. She knelt down, taking the pants with her, then after Katie steps out of them, tosses them aside.

Still kneeling, she was in perfect position to softly kiss Katie's stomach, trailing her tongue downward, to her belly button, and heading further south. She pushed the crotch of the panties aside, and suddenly thrust her tongue into Katie's pussy.

"Ah!" she yelped sharply, not expecting this. Kristen didn't stop, just kept licking. After a few moments she stood up and the two girls gave each other another deep kiss. From his vantage point, Mark could easily see tongues darting about. Both girls also had fingers in the other's cunt.

Katie broke the kiss, and whispered into Kristy's ear. "I see you found the panties I left you. Mark didn't know, I wanted it to be a surprise. I saw you watching yesterday. I know you enjoyed yourself."

Not at all a bit surprised at anything anymore, Kristy whispered back, "I'm glad you did. Now what?"

"I want to watch Mark fuck you." The emphasis was on the 'fuck.'

Both girls stepped back from each other a second, removing their panties so they were both completely naked. They looked over at Mark, who was still sitting there, watching. He had an erection again and was busily stroking his cock.

Kristen looked over to Kate, who was motioning her over with her eyes. Kristy walked over to her brother, knelt down, and took his dick deep into her mouth.

She looked up at him with eyes that screamed 'fuck me.' Freeing her mouth, she sat atop his lap, straddling him. She guided his cock into her, then started moving faster and faster, riding him hard.

"Oh, yes! Fuck me. Fuck your sister." She yelled, not caring about the volume. For the first time, she kissed her brother, thrusting her tongue into his mouth. It was the best kiss of her life. His hands cupped her ass as she rhythmically rocked up and down.

"I've wanted you for years."

Mark suddenly picked her up, carried her, and placed her on the ground on her back. During this, he had slipped out of her.

"No! Put it back inside me." Kristy ordered sharply. Mark happily obliged, thrusting into her hard.

Katie sat there, watching, fingering herself. Her boyfriend had his sister on her back and was fucking her. They were moaning and grunting. Their bodies writhed together in pleasure. It was arousing her to no end.

Nevertheless, she felt a little left out. They both had already cum. And by the looks at it both of them were about to again soon. Here she was fingering herself.

Kristen was still aroused from her earlier orgasm. It wasn't gonna take her long to get off. She was hornier than she had ever been before. "Normally I use condoms," she whispered into his ear.

"You're the only guy I've ever fucked without one...it feels great to have you inside of me. I.... I'm gonna cum soon." Her breathing was getting quick and heavy.

"Should I go get one? Or pull out?" her younger brother asked.

"No! I want you to cum inside me. I want to feel it."

"I want to fuck you from behind."

Mark quickly pulled out. Kristy got up on her hands and knees, and he quickly reentered. Her face was now about level with Katie's crotch. Realizing that they had both forgotten about Katie, and feeling bad, she told her to come closer. Now being fucked from behind, she dove in to her brother's girlfriend's pussy, eating her out.

Katie had been fingering herself this entire time, so it didn't take long to be on the verge of an orgasm. "Yea... oh.... eat... me....make...me...cum." Her entire body spasmed uncontrollably.

Mark watched intently. His sister was eating out his girlfriend. Just the thought was enough to make him ready to cum. "Here it comes, baby..."

"Yes!" Katie screamed, coming down from her orgasm. "Fuck her! Cum inside your sister."

Mark couldn't hold on any longer, and let go, shooting his jizz into his sister's pussy. "Kristy...ugh."

Feeling this was all Kristy needed to experience her second earth-shattering orgasm of the night. She made no attempt to hide the noise, screaming loudly as her body gave her more pleasure than she ever thought possible.

After it was done she just collapsed onto the floor.

Mark pulled out, and crawled over to Katie. He held her, stroked her forehead and caressed her softly. They lay there in each other's arms, smiling at each other.

Kristy, now coming down from it, wanted so much to be held like that. She longed for a loving embrace. But she realized her brother was with the other girl. She was just someone who he fucked. She was just the girl on the floor with cum dripping from her pussy, alone. Suddenly she missed her boyfriend.

Mark and Katie kissed each other, softly, lovingly. They drifted off to sleep in each other's arms.

Kristen didn't bother to move. She just wondered how she would handle this situation tomorrow.