At first Castiel thinks Gabriel and him have just turned into mass hoarders. With all the time on their hands while their Alphas are away working, a stack of pillows and blankets have found their way onto the couch.
But then one night when Michael, Sam, Lucifer, and Dean come home, he can smell the differences on his mate, and all is revealed.
So he hides it with cleverly placed vases full of fragrant flowers, and he tells Gabriel to avoid provoking their Alphas so they don’t get knotted and found out. He sneaks little bits of cologne to cover up the smell as two weeks go by.
That night while the Alphas are sleeping, Cas helps Gabriel to sneak out from under their arms and downstairs into the living room.
“Gabe, come here,” Castiel demands, and pulls him closer so he can sniff at his belly. When the strong smell of Alpha fades, Cas can smell the change in Gabriel’s scent. “Do I smell the same? Are we both pregnant?” He asks quietly, and Gabriel takes a turn smelling Cas.
“Shit, yeah, we both are. Is that why . . .”
He looks over to the mass of pillows and blankets on the couch, and Cas nods his head solemnly.
“What are we going to do? Lucifer is going to panic, and so is Dean --”
“Hey, calm down,” Gabe says, and cards his hands through Cas’ hair. It makes his rigid muscles go lax, and he falls into Gabriel’s arms. “They’re goin’ to be so happy about it, alright? And if not I’ll take care of you.”
“Gabe . . . I don’t want to get kicked out. What are we going to do if we get kicked out?”
“We won’t, I promise. We can tell them --”
“Cas? Gabe? Everything okay?” Sam asks groggily, padding down the stairs in a pair of low hanging sweatpants, rubbing the sleep from his eyes. Castiel watches nervously as Sam scents the air, nostrils flaring, and his eyes widen almost comically. “Are you . . . ?”
He leaves the question open, and he rushes over to smell them both, cupping their bellies in his hands. They’re still flat, but now Cas notices the slight swell outwards.
“I’m going to wake them up, you two cuddle up on the couch, okay?”
“I’m happy, I’m so, so happy,” he says, and he kisses them both solidly, licking into their mouths and pulling them close. All three of their foreheads press together, and they breathe the same air for a moment before Sam goes to wake up Michael, Lucifer, and Dean.
The urge to add more blankets to the pile makes Cas and Gabe rush to the closet to grab more to cuddle up with, and they curl around each other, their bellies between them guarded by their careful hands and a thick padding of pillows.
When footsteps come thundering down the stairs Castiel curls in closer to Gabriel, but they’re both pulled out of the bundle of blankets to be cradled by their Alphas.
Dean and Michael pull Castiel in close to sniff at his neck and kiss him anywhere they can reach, all the while their hands roam over his stomach.
Lucifer and Sam hold Gabriel even though he squirms, but eventually Castiel and Gabriel crawl back into their makeshift nest of sorts, and their Alphas pile in, too.
The next day Dean, Sam, Michael, and Lucifer help Gabriel and Castiel move their nest into the bed so no one suffers through any more neck cramps, or back cramps.
Nine months later three more little bodies join the dog-pile, all of them girls, and they take turns holding them on their chests while they sleep, passing their little bodies around like security blankets, but somehow they always end up between Cas and Gabe, Omega heat keeping the pups warm.
And another year later when they become pregnant again, they make another nest, even bigger than the last.