The whole crew stood shock-still in the doorway, staring straight ahead at the scene unfolding at the bar.

"Oh my," Inara gasped.

"Mei mei, don't look," Simon whispered.

"That no good mother…" Zoe murmured.

"But I thought…", Kaylee stammered.

"I'll kill him," Mal stated flatly.

"No," exclaimed River. "No interference! Research in progress."

River glided to the booth situated in a dark corner of the bar, the rest of the crew trailing hesitantly behind her to take their seats. River motioned politely to the waitress and ordered a few pitchers of the house brew and some snacks for the table.

"River, aren't you going to do something about that?"

Her eyes slid to the sight of a curvaceous whore pressed seductively up against Jayne, the woman's hands roaming everywhere they could reach. "Yes. I am going to observe. This should prove extremely educational."

"I don't get it, Riv," questioned Kaylee. "I thought you two were a couple now. It's been weeks since ya'll made your big announcement and I thought you were gettin' on real good."

Simon made a motion to stand up. "Come on, mei mei, let's go. I don't want to say I told you so but I don't think you should have to watch this."

River yanked Simon's arm down, pushing him back into his seat. "No!" She searched the distressed facial expressions of the crew she thought of as family and rolled her eyes. "The girl has introduced a control into her research. She must observe the reaction."

Zoe stared at River, understanding and a small smirk sliding over her usually stoic face. "You sayin' you did this?"

"Affirmative," River nodded. "She is a good specimen, is she not? Jayne prefers large breasts and overtly aggressive behaviors in his choice of compensated sexual partners. Her fee was a bit more than this girl had saved but the woman's physical attributes were optimal and she was very professional in her negotiations."

Kaylee giggled. "I woulda' loved to hear that conversation!"

"River, I'm sure there are other ways, more subtle ways, to determine Jayne's devotion to you," Inara soothed. "I fear this…umm, I mean she," Inara vaguely gestured to the blond prostitute currently scratching nails up Jayne's thighs, "well, she may be a difficult test for Jayne to pass."

River found her eyes sliding over to Jayne, now doubting for the first time her decision to introduce a control into her fledgling relationship with the mercenary. The intent was simple. Test his fidelity. Although she accepted that Jayne was not a skilled verbal communicator by nature, River needed assurance of his fidelity prior to initiating the next phase of the research she had planned.

She cringed slightly as she saw Jayne angle his body toward the whore. Upon closer observation of his facial expressions and body language, she obviously had miscalculated the outcome. He seemed entirely too attentive toward the women's overtures. Her heart clenched in her ribcage as his hand slipped possessively to her gluteus maximus. He's touching her ass, a panicked voice screamed inside her head.

"Oh my, " Inara whispered again.

"Oh shit," Zoe swore.

"That's it!" Mal stood, his chair crashing to the floor. "I'm going to kill him."

River watched as Jayne's steely glare bore into her before he smirked and drove his head into the women's neck, causing the whore to grab at his hair and laugh loudly. That was enough data for one night, she told herself before hurtling herself toward the exit.

She stopped briefly at the door, looked over her shoulder. "No harm will come to Jayne ," she threatened. "Dong ma? Leave him be." She stayed long enough to watch Simon sadly bow his head, Kaylee and Zoe nod, Mal re-holster his pistol and Inara lay a calming hand on her lover's shoulder. Confident that her family would not interfere, River slipped out into the darkness.

Xxxxxxxxxxxxxxxx

"Gorram it, girl! Get that gun outta my face!"

River lowered the weapon she didn't even realized was in her hand and placed it back under her pillow. She kicked the blanket off her legs and blinked up at a very infuriated-looking Jayne. She certainly hadn't expected for him to come to her bunk tonight, assuming he'd spend a fair share of it with the busty whore.

He was pacing her bunk like a wild animal and her body couldn't help but react. Jayne was very sexy when he was angry. River had already discovered this important piece of knowledge and used it to her benefit many times in the past few weeks. However, she did not know the cause of this particular anger and now that she knew his loyalty to her was faulty, River felt it best to push her sexual stimulation aside and deal with terminating their relationship. After hours sitting alone doing all the calculations, it was the only fair solution for both of them under the circumstances (although the realization did come with significant emotional trauma.)

"Jayne, I didn't expect you," she started blankly. "I'm sorry but I am unwillingly to engage in sexual activities with you tonight but perhaps we should talk."

"Talk, huh?" Jayne stopped in his tracks and spun to face her. His eyes practically glowed with anger. His right hand kept drifting to the butt of his gun. An involuntarily reaction to increased aggression, River surmised. "Don't reckon you had talkin' on your mind when ya' paid that whore!"

River only blinked in surprise.

Jayne took a few steps forward and pushed a shaking hand through his hair. "Think I'm too stupid to tell the difference between a whore looking for some coin and a whore who's already been paid? Gorram it, girl. What were ya' thinking?"

River bowed her head to stare at her hands in her lap. She had been convinced that testing his fidelity was the best available action prior to commencing the next phase of research. Now she had to admit that the control experiment had not only failed but had damaged the entire research. Jayne was hurt, she was heart-broken. Failure was one thing. A complete backfire was another but he deserved the truth.

She lifted her head, swiping the tear from her cheek. "Jayne," her breath hitched seeing him so angry and confused. "I have enjoyed these past weeks with you so much that I had hoped to initiate a next-level research project for us. However, due to the parameters of the project, our fidelity to one another would have been a requirement. "

Jayne huffed like he did when was thinking something through and came to a conclusion he didn't like.

"Come 'ere, girl," his tone less angry but clearly exasperated.

River pushed to her feet and crossed the room to him. In a quick, unexpected move, Jayne took off his shirt and threw it on the floor. He grabbed for her hand and placed it on the slight bite mark on his shoulder.

"Who did this?" he growled lowly at her.

"I did," she admitted shyly. "I believe that was from our session in the engine room."

"That's right," he pulled her hand to his neck. "And who did this?"

River observed the small dark contusion on his neck. Jayne called them love bites. "I did, last night."

"And how 'bout them scratches all down my back? Who gave me them?"

"I did," she smirked slightly, remembering a particularly enthusiastic session in the cargo bay.

"That's right." He yanked her hand and flattened her palm on the center of his chest. "Now pay attention. Who did this?"

River stared up at him in wonder as she felt his thundering heart beats through his sternum. "I did?"

"Damn straight, pretty girl. Why in the 'verse would I want someone else?"

With that River felt Jayne's lips crush against her own. Her hands slipped around his waist and clutched at his shoulder blades. Relief flooded through her body, washing away all tension and doubt, leaving only guilt in its wake.

"Jayne," she pulled back a bit to look up at him. "I'm sorry. I really am very sorry. Will you forgive me?"

River felt Jayne's eyes trail down her body. "Maybe." He slipped the strap of her nightgown off her right shoulder. "But I think you need some remindin' on how things are 'round here first." She felt his rough fingers slip the other strap off her left shoulder, causing the silk to pool at her feet as fierce heat and anticipation rippled through her.

Their sexual exploits often had her play the role of dominant but River sensed that, for now, she should simply stand there and let Jayne take the proverbial lead. A small smile curled her lips as she could practically feel his eyes roaming every inch of her now very nude body.

"Damn, girl," he groaned. "Turn around and put yer' hands on the bed."

River did as she was told. Her hair falling down her arms until she felt him sweep it up in his hands and splay it down her back. She grinned a bit to herself, knowing how Jayne adored her long brown hair. Her thoughts were interrupted by the subtle sounds of Jayne getting undressed behind. She turned to peer over her shoulders.

"Na-uh. Turn back around there, missy. No peeks for bad girls."

River smiled at this new game. She was rather intrigued at being placed in a decidedly submissive position, both literally and figuratively. The wetness and heat she felt indicated her body found it enjoyable as well. She leaned down a bit further and shifted her weight subtly from foot to foot, swaying her body back and forth. Submissive didn't mean powerless, she figured.

"Damn girl," his hands gripping her hips viciously, his erection grinding into her from behind. "You look like sin standing there like this."

River wiggled her hips a bit more, relishing this new game. "Am I still your girl, Jayne?"

In response, River felt Jayne push into her core. The glide of it sending shivers up her spine. A small moan escaped her lips.

"Jayne, I've been a bad girl," she said in a teasing yet sulky tone.

That seemed to have the desired effect. River felt her hair being wound around Jayne's left hand and his right hand grip harder against her right hip. His trusts become faster and harder. She tipped down to rest on her elbows, allowing him to sink even further into her. She pushes back against him, thrust for thrust, as she slips one hand between her legs to touch him gently as he slides steadily in an out. His moans are encouragement to fondle him a bit more firmly.

As the pressure builds in her, she finds her hand slipping forward to touch herself.

"Jayne," she whispers, encouraging him as her orgasm begins its ascent. "Jayne, please…"

She feels her hair tumble over her shoulder as he releases it. His hands are now practically circling her small waist, his middle fingers placed perfectly against pressure points on the inside of her pelvis. He slams into her now, all restraint abandoned in favor of ecstasy.

She hears her name tear from his throat as she feels his release inside her depths. The possessive sound of his voice triggers the avalanche of her excruciatingly powerful orgasm.

Just as she feels herself returning, he slips out from her and guides her gently onto the bed. His body stretches out beside her and the warmth of it relaxes her even more than she thought possible. Then again, River has always loved the feel of Jayne next to her. In fact, it was one of the primary reasons for this whole debacle. She snuggled her head into the crook of her neck and kissed gently at the soft skin, knowing for all the 'verse that she would be his as long as he desired her to be.

"Ummm, that was good, baby doll."

"Yes, I agree. Do you accept my apology?"

Jayne shifted to his side to face her, his hand trailing absently along the curve of her hip and down her thigh. "Sure, but can I ask a question?"

"Of course," she replied, propping her head up on her elbow to face him.

"What exactly is this next phase of research you were talkin' on that you needed to test my love fer' ya?"

"Matrimony."

She smiled and waited as the word seemed to bounce around in his brain. She giggled at the moment of his comprehension.

"Matrimony, you say?"

"Yes," she clarified. "Matrimony."

Jayne's hand cupped her face, his eyes burning with intensity. "You sayin' you want us to get married?"

She leaned in and kissed his lips softly. "Yes, my Jayne."

"Kinda quick dontcha' think? It ain't that I don't love ya', it's just a might soon to be talkin' 'bout getting hitched."

"Yes, that's fine. Not to worry. We can commence other research projects for a while until both partners are adequately prepared for lifetime commitments to one another."

"Ya?" He smiled and kissed her softly. "What kind of research we talkin' on?"

"Progeny," she smirked.

"Progeny?"

River giggled at the sight of the new word bouncing around her lover's brain. Comprehension was only a matter of time. She was a very thorough researcher. She could wait.