Mary stood frozen in the doorway, eyes wide. Oh. Oh.
When she searched the bunker looking for her boys, this was not what she expected to find. And when she'd heard the grunting and groaning coming through Dean's cracked bedroom door, she expected to push it open and see him working out.
Although... What he was doing could certainly be considered a workout, if the way he was white-knuckling the blanket under him and arching his back was any indication. Even if Sam was the one doing most of the work, on his knees above Dean, abs clenched and arms corded tight as he pounded his hips.
And then he looked up and froze in place after a hard thrust and Mary realized that she probably should've left as soon as she realized what was going on.
Dean groaned after a moment, squirming in place and complaining, "Sam, c'mon man, fuck me," and Mary lost her breath.
"Mom," Sam said, half acknowledging Mary's presence and half informing Dean of it.
The jerk of movement from Dean at the word drew Mary's attention, breaking her stare with Sam, and she watched his erection pulse against his stomach, dripping precum. "Fuck, yeah, Mom, wanna fuck Mom, too," Dean groaned, grinding his hips against Sam's.
Sam finally looked down at him and clarified, "Dean. Mom's here."
When Dean opened his eyes and tilted his head back to look upside down at Mary, she bit her lip at the way his lips, full and damp and kiss-swollen, parted, his mouth pulled open from the angle. She remembered that mouth at her breast once upon a time and wondered where her motherly instincts went. She most definitely should not desire that mouth at her breast again.
"Mom," Dean said, sounding dumbfounded and ruined, and Mary watched his hand let go of the blanket to fly to his cock and for a moment she thought he was hiding it from her, until she saw his fingers wrap around it tightly and stroke.
"Dean," she replied breathlessly. She needed to leave. She needed to leave now, this was completely inappropriate, but instead of taking a step back, she moved forward. Movement from Sam drew her attention, and she watched as he pulled back from Dean. She froze again, worried he was stopping, but after the slow drag back, he pushed back forward. Dean moaned. So did Mary.
Reaching out with one hand beckoning her, Sam repeated, "Mom."
Mary stepped forward again, half mesmerized. As she rounded the corner of the bed, her gaze moved to where her boys were connected and she gasped. She wasn't an idiot, she knew what they were doing, but she didn't expect the sheer size of Sam, buried deep in his brother, stretching Dean's ass wide. "Oh my god," she breathed.
"Mom," Sam said again, and Mary slowly dragged her gaze back to his. "Come on."
"Yeah," Dean added, holding his cock upright by the base. "Come on my dick." He moaned, clearly picturing his words as he said, "Come all over my dick."
"Dean," Sam said quietly, a warning to not scare Mary off.
He didn't need to be concerned, as Dean's words made Mary clench, and she finally gave up the fight to pretend she wasn't completely aroused by what she was seeing, and that she didn't want to do exactly what Dean suggested.
Mary stripped quickly, the boys watching her as Sam continued to lazily stroke into Dean, and just as Mary was shedding the last of her clothes, Dean held out his hand. "Gimme those."
With a half-smile, Mary stepped up to the side of the bed and dropped her panties into Dean's hand, watching him bring them up to his face. The thought flitted across her mind that he was just like his father that way, but she knew better than to say it.
Distracted by watching Dean, Mary didn't notice Sam moving until his hand slipped between her thighs, and she stumbled into the side of the bed as her knees tried to give out beneath her.
"You're so wet," Sam said, his voice low and warm and awed.
Dean made a noise of agreement, and Mary flushed slightly as she realized Dean hadn't needed to touch her to know that she was soaked for them, because of them.
Curling his fingers in a come hither motion that had him dipping into her, Sam coaxed, "Come up here, Mom."
Mary climbed up on the bed without further incentive and knelt next to her boys, slipping her arms over Sam's shoulders and kissing him hard. He slid two fingers into her and she felt him thrust his hips hard, heard the muffled groan from Dean.
"Next time I'm gonna fuck you," Sam promised, nipping at Mary's lips, jaw, down her throat as he growled the words. Her breathy reply of "yes" was lost between them as he continued, "but this time it's Dean's turn." He kissed her again, devouring her mouth, before pulling back and manhandling her so she was straddling Dean's waist, facing him.
Looking down at him, Mary saw Dean watching with hooded eyes, his face flushed, her panties in his mouth. "Taste good, sweetheart?" Dean moaned and nodded and Mary reached between her thighs, gathering up her arousal. "Do you want more?" she asked, offering her fingers to him.
Dean pulled the panties out of his mouth, and Mary brushed her fingertips across his lower up. As Dean grabbed her wrist to lick her fingers clean, Sam took her by the hips, moving her back where he wanted her, and she had to bend over, bracing herself on her free hand. A moment later, she felt Dean's hard cock at her entrance, and Sam helped guide her down until she was fully seated.
She didn't even notice right away that Dean held her fingers between his teeth, straining to not bite down too hard as he was wrapped up in the sensation of filling his mother and being filled by his brother at the same time.
"Dean's close," Sam said, squeezing Mary's hips. "He might come before you."
Dean made a disgruntled noise, mumbling, "Hey!" around Mary's fingers.
Mary shook her head, pulling her hand away from him and using it to help keep herself up. "Just fuck me," she breathed, bending down to kiss Dean and licking the taste of herself from his tongue. She let Sam guide her into a rhythm, both of them moving together, Dean writhing beneath them.
And then one of Sam's hands slipped from her hip to between her thighs, rubbing over her clit and Mary swore into Dean's mouth, breaking the kiss to pant for breath. She'd never been built up so quickly, never been so close to coming from so little.
Then again, she'd never walked in on two gorgeous men fucking each other before. The fact that they were her sons... Well, that just made it better.
They sped up, Mary and Sam moving in tandem as Dean babbled their names, his body tense on the bed, his eyes glassy and little delirious. He was so close, she could see it on his face, and the fact that she'd never seen that expression on him before didn't make a difference. She jerked, bumping against Sam and disrupting the rhythm.
Sam grabbed one of her hands, pulling it back so she was once again with her weight on one arm, and guided it to her clit. "Touch yourself," he demanded, and took both hips in his hands again, moving her how he wanted.
And how he wanted was a couple of quick thrusts followed by a deep, dirty grind on Dean's cock, the pressure of it bottoming out inside her making her groan. She moved her fingers over her clit as quickly as she could, clenching around Dean.
Losing the ability to hold back, Dean gripped Mary's thighs, fingers digging in as he tried to thrust further inside, his cock pulsing his orgasm into her.
Mary came just moments later with a cry, and fell forward across Dean's chest, shuddering. He wrapped his arms around her, holding her as she writhed through the aftershocks.
As they both came down, Sam chased his own climax, pounding roughly into Dean's ass and staring down at the place the three of them were joined. It was watching the trickle of cum slip out of Mary and down Dean's cock that set him off, and he let out a tight growl as he came, filling his brother the same way Dean had filled Mary.
Pulling out carefully, Sam collapsed to the side, catching his breath.
Mary turned her head out of Dean's shoulder as they all calmed and said, "Well. This wasn't what I expected when I came here."
Sam just looked at her, but Dean tensed. "Are you upset?"
Lifting her head, Mary smiled down at him. "No, honey, I'm not upset," she assured him, kissing him lightly. "I think I'll be upset if this never happens again, though."
With overlapping voices, both of them assured her that it would definitely happen again, and Mary grinned, shifting to Dean's other side so he was sandwiched between her and Sam.
"Good."