A\N; I got the idea for this from an OTP prompt: Imagine character A accidentally catching character B masturbating. Character B does not notice they have an audience and continues what they're doing, including saying things like how much they want character A to fuck them. Character A finally pipes up, "You know, that could be arranged, if you'd like…" In this story is an AU, Lightning is Serah's step-sister and her hair is white instead of Pink.

Returning from a mission, Lightning slammed the door behind her. Though it was successful, the mission was more difficult than it should be. "I hate working with amateurs." Lightning sighed. She lost a numbers of times, she had to save the rookies from death. The sergeant thought it will be best, to have a cold shower to calm her nerves.

As she walked upstairs, she opened her vest and ran her fingers through her snowy white locks. Because the death of her step-parents and real parents made her cold as ice and hard as the steel in her Gunblade Flamberge. After their deaths, she needed to prove that she's not a helpless child, and can be proved for herself and for her dear step-sister Serah on her own. Not needing help from no one. The only one she let get close to her was Serah.

She was the only one who understood Lightning. The only one who can melt her cold heart. However, nowadays Serah may not able to anymore. her warm love was for someone else. Snow. When she think, sees or hears that man. Her icy heart changes to a raging inferno of anger. "Now I really need a shower." before she did that. Lightning thought it best to check up on her sister. See if she's alright. Her behaviour was odd these past few days.

Getting close to Serah room she heard gasps and moans. Strangely, it was coming from her own room. Concerned, opened the door a bit and was shocked to see Serah masturbating on Lighting's bed, her fingers slammed in her pussy. The other hand was up her shirt and rubbed her nipple. Lightning knows she shouldn't see this, but she can't tear her eyes off. Lightning then realized Serah must of be think of him.

That guy really needs to learn to put on a fucking shirt. Serah had often said she liked muscles. Not wanting to see or hear any more of this, Lightning resume her way to the bathroom to take a very cold shower and maybe have a drink. "Lightning!" that made said soldier stop in her tracks. "D-Did she?" wanting to make sure she's not hearing things, went back to her spot. And sure enough.

Serah did say her name. Multiple times in fact. Lightning had heard Serah say her name all the time, Loving, teasing, happy, scolding, angry, sad, hurt. Never like this. Never with lust, need and want. Lightning contemplated why her step-sister is like this. Look down at her abs, it clicked. Whenever she would walk around in a tank-top, sports-bra or have her vest open. Serah would always look at her abs she got during her time in the military.

Serah's cheeks would turn red when she looked at the white-haired soldier's muscles. Lightning chuckled. "How did I not see this. God, I'm dense." she said shaking her head. With this new information, Lightning enjoyed the show. Letting they years of hidden lust and desire for Serah take over her. Lightning had watched Serah grow over the years and she grown into a fine woman. Knowing their not related by blood, Lightning decided to make Serah hers.

"Why did I go out with Snow! Lightning is much sexier and better them him. God, I love seeing that hot sweaty body of hers." Lightning grinned as Serah said that. Lightning would make her presence known. But waited until she hears say a certain phrase. A curtain request. "Lightning! I want you to fuck me!" that's the one.

Pushing the door open, Lightning spoke in a very alluring tone. "You know, that could be arranged, if you'd like…" the younger step-sibling shot up and quickly cover herself. She was horrified to know that Lightning saw her pleasing herself.

The look in Lightning's eyes wasn't disgust, but the opposite. It was a look Serah hadn't seen before. It was a hungry stare, Lightning slowly approached her. Unclipping her Gunblade, let it fall the floor, then took off her vest, gloves and black sleeve. Slowly she unzipped her turtleneck, so she showed a bit of her cleavage. Serah rubbed her bottom lip. Like with Lightning. Serah let her own hidden feelings for Lightning take hold. "You're so hot." Serah said in a daze.

"Thank you." Lightning then cupped Serah's face, pulling her up and stop right when their lips are about to touch. Serah lost herself in the white-haired beauty's gaze. Those sapphire eyes matched so well with her snowy locks. It really brings them out.

"Tell Serah..." Lightning's thumbs rubbed the younger girl's bottom lip. "Did you kiss that blond imbecile yet?" Serah shook her head and shivered by Lightning's cool breath pass over on her lips. Another thing she found attractive about is how confident and reassuring Lightning is.

"If I kissed you, would it be your first?"

"Yes...I want you to be my first." Lightning latched on to Serah's. Licking and sucking them finding her lips soft and sweet. Finding that fitting as that's a kind of person Serah is. While Lightning was enjoying kissing Serah moved her hands under her shirt, and began to knead them making Serah moans into the kiss. Lightning noticed her little sister's chest has grown bigger from the last time she (by accident) felt them.

The kiss evolved into a hungry, passionate, heated make out session. Lightning's tongue coiled and wrestled with Serah's. Lust grew more and more, within their bodies. Serah ran her fingers through the white hair she loves so much. Loving its softness, the colour everything about it and the person attach to it. The satiation of kissing Lightning was too much for her that she was about to have an orgasm.

Maybe because of Lightning's strong, caring hands playing with her chest. When Lightning pinched her nipples, Serah arched her back and moaned loudly in her new lover's mouth. Instinctively holding Lightning more closely. Climaxing all over Lightning's sheets. Due to her enhanced senses, Lightning can smell Serah's juices. It began to drive her wild.

Breaking the kiss, the two took the time to catch there breath. Looking at each other lovingly. "My breasts. I always wanted you to suck on them." Serah panted, opening her shirt up and pulling up her bra, showing Lightning her harden nipples. Seeing this, Lightning licked her lips. Eyeing her like a hungry wolf. Unable to hold back this heated desire, took one of Serah's nipples in her mouth.

Serah moaned loudly grabbing a fits full of Lightning's hair. Serah loved how gentle and loving Lightning is with her nipples. It's the same way she treats her and she loves it. Feeling a soft tongue cycle her nipple made her moan out her first love's name. Grinding her wet core on Lightning's muscular thigh. With Serah's nipple in her mouth Lightning slipped her free hand under Serah's panties.

Rubbing her clit with her middle finger and her lips with her index and ring finger. She felt very wet. "LIGHTNING!" Serah cried out. Her legs wrapped around the soldier's arm. Lightning's fingers felt so much better then her own. Thinking it couldn't get any better. It did as the finger on her clit went deep inside her. Causing her yell in surprise.

The single digit moved furiously in her slit. It was unbelievable, how good Lighting's single finger feels. "MMMore!" Serah pleaded. Granting what she wants, Lightning added another finger. Releasing the nipple in her mouth, Lightning moved up and held her lover close. Serah wrapper her arms around her dear soldier and screamed in pleasure. Her inner walls tighten in Lighting's fingers. Serah moved her hips against those amazing finger.

Biting her lips, she felt it hit a currant spot "Right there! Right there! Don't stop!" finding out her dearest favourite spot, focused on it. Serah was in so much ecstasy that she began to droll. "Light, I'm-" Serah wasn't able to finch her sentences and came again, and she came hard, screaming Lightning's name in the processes.

Pulling out her finger, Lightning licked off Serah's essences. "You taste good Serah.." she growled lustfully. "Want me to eat you out?"

"W-Well, sis...can you..." to embarrassed to say it, she rolled over and stuck her butt in the air. Pulling up her skirt higher she pointed where she wants Lightning's tongue to be. Her ass. Lightning's eyes widen, then smirked at her request. "Naughty girl, Serah." Lightning then firmly grasped her step-sibling's well rounded rear.

Spreading her cheeks, slowly moved closer to Serah's ass then gave a quick flick with her tongue. Causing Serah to whimper. "Ready?"Lightning asked. The only response Serah could give was a nod. Bracing herself, she felt Lightning gently licking her hole. When it's nice and wet, Lightning slow stuck her tongue in. Serah clenched the bed sheets. "Lliiightning!" she moaned out. She felt a bit of pain at first, but Lightning went slow until she got us to it then it began to feel good.

Knowing it was alright to go harder. Went in deeper and moved as fast as she could. Serah lifted her head and shouting Lightning's name over and over again. Her was glad that she was in position because slutty expression she was making would be too embarrassing for Lightning to see. The intense pleasure from her ass was to much that she couldn't let Lightning know that she's cumming again.

With one final cry, Serah climax once more. This time, Lightning latched on Serah's pussy and drank it all. "I'll say it again; you taste good Serah. I can't wait for more." Lightning said licking her lips. She lay by Serah's side held her in a warm embrace. "How was your first time?" Lightning asked, lightly stroking Serah's hair.

"Amazing!" Serah responded nuzzling under Lightning's chin. "I don't think I'll be able to walk tomorrow."

"You wanted me to lick your ass. The face your made was exotic." Lightning chuckled.

"Wait, how did you know?!" Lightning answered her question by pointing at a mirro that at to the side of her bed. The angle it was position allowed Lightning to see the face Serah was making when her was eating out her ass. Serah covered her face in shame, but Lightning pulled and looked at her lovingly. "It's alright Serah." she then leaned in closer and whispered in Serah's ear. "I was kind of hot."

As she was to say something, a yawn escaped Serah' lips. "Let's get some sleep, okay?" Lightning suggested. Serah nodded sleepily. Lightning helped her lover out of her clothes and in a nightgown. When she was all set Lightning slipped on her tank-top and boy shorts. Once they where cuddled up the blanket.

Lightning gave Serah a quick peck and said with all her heart. "I love you Serah. I love so much."

"I love you to. And thank you for giving me all your love."