His back against the headboard, Cas's back against his chest. Dark hair brushing against his chin and cheek, grabbing the angel's hand and intertwining their fingers. Restrained moans and wiggles against his growing erection (he didn't want that to happen, tonight's focus being on the angel in his lap). It is perfect.
Between Cas's legs lies Dean, licking and nipping at his thighs, head bobbing up and down, taking in as much as he could of Cas and sucking in his cheeks. The more he writhed around the faster he went, those pants and gasps being the only song he wanted to hear. The noises, the sparse but steady drops of come already beginning to leak out of him only encouraged him. He tastes so good, so god damn good. Dean's hands push his thighs further apart. Have to make sure Sam sees it all.
He does, and it's driving him mad. As much as he enjoys to sit on the sidelines and watch, seeing Cas disappear inside his brother, he greedily wants to be beside him, because that's what big brothers do, right? Share with his little brother? But there is a different pleasure to be found in being passive, a clear-headedness. It also makes being involved later on more significant. More intense.
Cas runs his fingers through Dean's hair, causing him to look up at both of them. After a quick wink and smile, mouth full, he resumed. Sam couldn't catch Cas rolling his eyes, but he did see the corner of his mouth turn up when he leaned his head back. Yeah, Dean was a cocky little shit, but when those pink lips stretch around you, he has every right to be.
Cas is closing in, breath becoming quicker. Sam egged him on with supportive whispers, do it for me, do it for us. The grip on his hand became a little tighter. Their beautiful little angel, so vulnerable and so human, allowing himself to be for the brothers.
Dean never slows his pace as Cas orgasms; he wants it all, needs to hear Cas fail muting his cries. His body goes rigid and unwinds as slow as sap. Still being relatively new to sex, the intensity of his orgasms take him by surprise, which Sam and Dean see as a fun game. To see Cas so sated post-sex, sleepy and weakened to their more tender caresses, was a pretty good reward.
Once Dean pushed himself up to his knees, he couldn't ignore the urge to lean over Cas and exhibit no hesitation by kissing Sam. The taste of Cas, his brother, on his tongue; sparks exploded into existence behind his eyelids. He shouldn't feel this way, so... good. Not because it was wrong – he didn't give two damn about what society would say about this class of relationship. But because he thought he didn't deserve it. To be satisfied and content and to look forward to waking up the next day. He knew they felt the same way. Guess they'd have to keep proving each other wrong. Every day, several time a day if they had to.