Dean woke up to the sound of plastic shopping bags rustling, and Cas' humming. He rolled over to see his mate, dressed in pajama pants and a t-shirt, contentedly sorting through the bags of clothes they had purchased the day before. Dean propped himself up on one elbow to watch.

Cas looked so pleased. A soft smile graced his warm features as he pulled one item at a time from the bags, hanging them up in the closet or folding them into the drawers of his dresser.

"Havin' fun there, babe?" Dean chuckled. Cas looked up, happiness written all over his face.

"I am," he smiled. He moved over to the bed and leaned down to give Dean a quick kiss. Dean wrapped a hand up around the back of Cas' neck, holding him there and savoring the feel of his lips.

With a hum of enjoyment, Cas lingered a moment. When Dean felt him smile against his mouth, he let Cas go. Cas turned back to his task, picking up the bag closest to him. He reached inside once more for the next item as Dean, still naked, adjusted the blankets around him and sat himself up against the headboard to watch, his hands linked behind his head.

Cas lifted a package out of the bag and paused. Tilting his head at the package, Cas' brow furrowed in confusion.

"Huh," Cas turned the package over in his hands.

"What?" Dean was so busy watching Cas' face, he hadn't noticed the package in his hands.

"Wonder how these ended up in here?" He held the package up for Dean to see.

Dean's mouth went dry when his eyes shifted to the package of women's satin, bikini underwear in his mate's hand. He was instantly flooded with the memory of holding that package at the store, when he was surprised by the sales clerk, nearly knocking over the entire underwear display. He had wondered what Cas would look like in something like those. Dean's treacherous cock twitched at the sight of them in Cas' hand.

"Uh...," Dean cleared his throat, "...no idea." A hot blush started its way up Dean's chest. Cas raised an eyebrow at him skeptically as the rush of heat reached Dean's face. Dean dropped his arms down to his lap.

"No idea, huh?" Cas smirked. Dean shifted, embarrassed, on the bed. Package still in hand, Cas crawled onto the bed over his Alpha, pinning Dean's legs under the covers. Dean's face was beet red, and he had trouble meeting Cas' eye. "You sure about that?" Cas nuzzled at Dean's neck. He reached his free hand down to rub at Dean's cock through the blankets. Dean nodded, sighing. "You sure you didn't pick these up to check out the model on the cover?" Cas continued. "That's the closest thing to porn you've looked at in months, isn't it?" Cas kept up his attentions to Dean's quickly hardening cock. "I think you wanted a peek at the other side of that coin," Cas' voice dropped dangerously low. Dean shook his head. "You were picturing what the rest of her body looked like, weren't you?" Cas' grip tightened and Dean hissed at the nearly-too-tight clench of his fist.

"YOU!" Dean almost shouted. Cas froze. He backed up enough to look at Dean's face as his blush deepened further.

"What?" Cas whispered, confused. Dean's eyes dropped.

"I...," Dean heaved a sigh, "...I was picturing you in them." Dean could feel the sweat breaking out on his forehead and upper lip, he was so embarrassed. How would Cas react to that? Laugh? Yell? ...Make him leave?

Cas sat back on Dean's legs, staring at him with that piercing gaze.

"You pictured...," his eyes went wide, brow raising in surprise, "me in them?" That was not what he was expecting.

After a long moment, Dean nodded, still unable to meet the Omega's eye.

A wicked grin crept across Cas' features.

"Well," he rumbled seductively, leaning back in to run his lips along Dean's, "I guess we'll just have to find out, huh?"

Before Dean could process what his mate had just said, Cas was off the bed and out of the room, package in hand.

Dean sat in stunned silence as Cas closed the bathroom door. He did his best to wrap his brain around what was happening as he listened to the sound of Cas tearing into the package.

Long, silent minutes passed and Dean was sure Cas had changed his mind. Dean's erection began to flag as time ticked by.

At long last, Dean tossed back the covers and made to climb out of bed, ready to tell his Omega to just forget about it.

"Cas-,"

He didn't make it that far.

The bathroom door swung open and Cas stood there, flushed and glassy-eyed, in nothing but a pair of blue, satin panties.

Dean's cock responded so quickly to the sight it almost hurt.

"Fuck!" he breathed. His eyes raked slowly over Cas' body. A gorgeous flush colored his cheeks and spread down his chest. Dean's gaze traveled the length of Cas' body. He stared at the curve of the Omega's stomach, just starting to show with the pregnancy. Dean's eyes slipped down to the edge of the panties, riding low beneath the swell of his baby bump. Dean's gaze settled on Cas' cock, full and firm, poking out over the top of the panties. "Holy shit, that's hot!" Dean moaned.

"Do you like them?" Cas moved toward the bed and Dean, seated on the edge of it.

"Like them?" Dean huffed a laugh as Cas stopped just inside his spread legs. Dean slid his hands up the outside of Cas' thighs as his eyes devoured the sight before him. "Baby, I can hardly keep from cumming all over myself right now!"

A grin spread across Cas' face as he looked down to see his Alpha's knot already showing signs of swelling. He set his hands on Dean's shoulders. Dean let his own hands slide up and down Cas' hips, savoring the feel of both skin and fabric.

"Good," Cas leaned down to kiss his Alpha. "Because I want you to fuck me in them." Thrusting his tongue deep into Dean's mouth, Cas climbed up over his lap.

Breaking their heated kiss, Cas slid his arms over Dean's shoulders, leaning up, and pressed his leaking cock and the soft, silky panties against Dean's firm chest. Cas gazed down into the lust-hungry eyes of his mate as he rubbed himself against Dean.

Dean's powerful hands slid across the delicate fabric to grip the firm globes of Cas' ass. Cas keened as Dean's hands began to knead his muscles. He tipped his head back, soaking in the sensation, and his eyes slipped shut.

With a strong and sudden movement, Dean pulled Cas down to the bed and climbed up over him, settling between his legs. Dean leaned up to take in the sight of his Omega spread out beneath him on the bed.

Legs spread wide, cock flushed and leaking precum onto the slippery fabric, Cas was a sight to behold.

"Fuck, Cas," Dean panted, barely able to hold himself back, "you are the hottest fucking thing I've ever seen." Dean ran his hands up Cas' thighs slowly. With a low, breathy moan, Cas' eyes fluttered shut and a wave of arousal swept through him. Dean caught the scent of it, and pressed Cas' legs wider, folding them up toward his chest.

Dean watched the panties pulled taught across Cas' ass, pressing against his skin. He held Cas there, and stared.

"You like how they feel, baby?" Dean's low, growling voice made Cas shiver, and another wave of arousal made a pulse of slick slip from him. Dean's eyes went wide as he watched the sweet evidence of Cas' enjoyment spread a dark, wet spot in the panties. "Fuck, yeah, you do." Dean slid one hand down to rub at Cas' hole through the soft fabric. "Shit, this is even better than I imagined," Dean pressed his thumb against Cas' opening, teasing him with the digit and the slick slide of the wet fabric. Dean leaned down to mouth at Cas' neck, and Cas wrapped his arms up around him. "Now, what was that you said about wanting me to fuck you in them?"

"Mmmm," Cas hummed in agreement, pulling Dean to his mouth. He kissed him deeply, then slid one hand to his chest and pressed back. "But first," he smiled darkly up at Dean, "I want you to eat me out." Dean's eyes went wide at that and his mouth dropped open. How was it possible for Cas to get even hotter in that moment?

Eager to comply with his Omega's wants, Dean tugged the panties down Cas' legs till they were loose around his calves. With a low rumbling in his chest, Dean pressed Cas' knees further up and apart. He leaned down, nipping at the tender skin of Cas' inner thigh as he made his way to the delicious heat of his entrance.

Cas moaned as Dean's tongue found its mark. His hands shifted down to grip Dean's hair and shoulders as he rocked back onto the warm, wet feel of his mouth. Dean sighed as he felt his Omega's slick pulse from him and slip across his tongue. He indulged in the flavor of Cas, taking his time as he licked slowly up and down across his furled hole. Dean's body hummed with anticipation, but he was even more desperate to take his mate apart a piece at a time.

Writhing in pleasure, Cas clutched at Dean, gripping his shoulder tight, and thrusting himself back against Dean's teasing mouth. Dean flicked his tongue over Cas' entrance quickly a few times, making him arch off the bed and a gush of slick spill from him. Dean moaned at the reaction, pressing forward to lick and suck up his arousal.

"Oh, god, Dean!" Cas panted, "love it when you fuck me with your tongue! That's it! Oh! You feel so good!" Dean moaned again, pressing deeper and breaching Cas with his tongue. Cas' legs began to shake on either side of Dean's head, and his slick came in waves. He knew his Omega was close. Dean slipped two fingers in along with his tongue to stretch Cas open. "Yes!" Cas shouted, lost in the pleasure of Dean's ministrations. He was so very close.

Dean pulled back.

Sitting back on his heels, Dean kept his two fingers inside Cas. He pumped and scissored them as his confused Omega looked up at him. It took Cas a few moments to focus. When he did, he furrowed his brow at the lust filled smirk on his Alpha's face.

"...Dean?" he panted.

Dean thrust a third finger deep inside his mate. Cas arched up off the bed as Dean brushed against his prostate. It was painfully too little.

"Wanna make you cum in your panties, Cas," Dean rumbled, "just like you asked for." He pumped his fingers in and out, stretching Cas wide. "And I want you to do it on my cock."

Cas moaned at that.

"Yes, Dean! Want your cock so badly!" His body responded to the touch of his Alpha, spilling more slick to ready the way for him. Dean pulled his soaked fingers from Cas and coated himself in the sweet, wet gloss of his Omega. When he had covered himself with the delicious slick, he brought his hand up to his mouth and licked the excess from his fingers.

With a thrust of his hips and a desperate whine, Cas reached up and gripped Dean's wrist. He pulled it down to his own mouth, sucking Dean's fingers past his own lips and savoring himself on Dean's skin.

"Fuck, Cas!" Dean moaned. With his free hand, he lined himself up with Cas' entrance. When the head of his aching cock pressed passed the tight ring of muscle, Cas' mouth dropped open in a silent cry of pleasure. Dean pulled his hand back, grabbing the panties still around Cas' calves, and slid the silky fabric back up Cas' legs as he sank into him.

Dean tugged them up as far as they would go over Cas' ass. He felt the waistband of them press against his cock as he rocked out and thrust back into Cas' tight, wet heat. Dean made sure to slip them up over Cas' cock, concealing it beneath the soft, pale, blue of the satin. He gripped Cas by the hips, holding the panties in place, tight across Cas' cock.

"Oh, Deeeean!" Cas moaned as the man above him slid almost all the way out before snapping his hips forward against his own. Cas' breath came out in tiny, panting huffs as Dean set a deep, steady rhythm, and he wrapped his hands around Dean's forearms. Dean looked down to watch the head of Cas' leaking cock drag back and forth across the inside of the panties with each one of Dean's thrusts. He stared, hypnotized, as a small smear of wet precum darkened the fabric and the moisture spread.

The sweet, teasing sensation of the silky fabric rubbing against the head of Cas' cock made him whine with pleasure, setting his nerves aflame. Cas' firm erection tented the panties up obscenely, and Dean drank in the sight. His knot, which had started to swell the moment Cas had opened the bathroom door, was growing larger, harder with each thrust.

A keening moan, continuous and addictive, poured from Cas as he felt Dean begin to catch at his rim. Cas' grip on Dean's arms tightened.

"That's it, baby," Dean panted, speeding up the motion of his hips and thrusting faster, harder. "Oh, fuck! Let me see you cum Cas! Cum in your pretty, little panties! Fuck, baby, yes! Cum for me!" Cas' head pressed back and he arched up once more as his muscles seized and he spilled his release into the thin, silky fabric.

Dean watched in awe as the fabric pulsed against the head of Cas' cock, turning dark and shiny as his cum soaked through the cloth.

"Oh, shit, Cas! Shit!" Dean's hips sped up more as he felt Cas clench around him, and his channel slick more. With a final, slippery thrust, Dean's knot popped passed the tight ring of Cas' spasming muscle. Dean's release burst from him almost forcefully, and his whole body shuddered with the waves of his release.

Shaking, Dean dropped forward onto his elbows, hovering over Cas. They panted against one another, their bodies shaking with the intensity of their encounter.

"Damn, Cas," Dean breathed when he could finally speak. Cas nodded in response, still not able to form words.

When strength returned to him, Dean sat up as best he could, propping himself up on one arm, still locked to his mate. They both looked down at the messed panties still pulled taught across Cas' hips.

"We should get these off you before they dry to your skin," Dean hooked a finger under the waistband and started to tug the soaked fabric off. Cas lent a clumsy hand, still reeling from his orgasm. He nodded to Dean again.

When they had extracted Cas from the panties, Dean made to toss them to the floor. Cas caught his wrist. He plucked the panties from Dean's hand. Straightening them out, Cas held them up to inspect them.

The fabric was thoroughly soaked, and Cas' release was smeared thickly across the inside.

Cas smiled up at the fabric.

"Damn, baby," Dean chuckled, "looks like we ruined 'em." Cas shifted his gaze up to Dean. His blue eyes were bright and mischievous as he tossed the panties to the floor. Reaching up, he wrapped his arms around Dean's neck and pulled him down for a deep, heated kiss. He brushed his lips across Dean's, smiling as he spoke.

"Good thing they come in packs of three."