AN: this story contains (largely implied) mpreg of an interspecies variety. If that doesn't butter your crumpet, now would be the time to turn back. Otherwise, welcome; please continue on for unapologetic domestic fluffiness and happy endings. Also, 'Adad is Khuzdul for father, according to the sources I could find. Not definitive, but I like it.
"My Beard"
My beard grows down to my toes,
I never wears no clothes,
I wraps my hair
Around my bare,
And down the road I goes.
-Shel Silverstein
The piercing racket of a scream tore Bilbo from a deep, restful sleep, and sent him jerking up from the feather mattress, one arm clutching protective and tight around the slight pot of his stomach. Thorin, who had a mere instant before been curled snugly against Bilbo's front, was already on his feet, tense as a coiled spring and reaching for his sword.
"Stay here," Thorin said sharply, already dashing towards their bedroom door, utterly unconcerned for his nudity. Bilbo had already thrown back the quilts and was barely a pace behind, snatching up a nightshirt that simply happened to be in reach.
"Don't be stupid," he snapped, yanking the nightshirt over his head without pausing. His heart was pounding in his throat, thunderous and painful, and he could see Thorin's eyes flashing like blue fire. "That was Belladonna—"
The children still slept in rooms attached to their parents' spacious solar, though Frerin had begun clucking for his own private space farther down the family wing, like Fili and Kili enjoyed. Bursting into the solar, the bedroom door crashing open before him, Thorin quickly scanned the shadows for lurking dangers, closing the distance to their daughter's bedroom door with hasty strides.
That door met with a similar fate as the first, no match for a ferocious dwarven father seeking to protect, and the bang of it being flung open was punctuated by another horrified shriek, this one muffled by quilts and goose down. There in the warm light of lit braziers, sprawled face-down across her tangled bedding, lay their darling daughter, apparently alone and unbloodied.
Reassured by the apparent lack of knife-wielding assassins, but not yet entirely assured of their daughter's well-being, Bilbo shoved past Thorin's naked bulk and rushed over to the bed, dropping to sit and putting both hands on Belladonna's back, smoothing over the rumpled lines of her soft nightgown.
"Hush, my darling, what's wrong? Are you hurt?" Rather troublingly, Belladonna didn't answer, except to hunch down against the blankets, wrapping her arms around the back of her head. Bilbo's heart gave a lurch, panic spiking again. "Bellie, are you hurt, I said—"
"Answer your father," Thorin said hotly, his tone brooking no argument, and the girl flinched visibly, twisting just enough to speak from under the shelter of her arms. Thorin so rarely raised his voice to their children that the sound was always shocking and the reaction swift.
"I'm not hurt." Her words were strained with tears and frustration, and Bilbo kept up his soothing stroking along her back and the long chestnut waves of her hair, feeling her quivering. "It's... it's nothing. It's fine. I'm sorry I shouted."
"What's going— Ah! 'Adad!" Bilbo turned in time to see Frerin skid to a stop just inside his sister's bedroom, both hands coming up to desperately cover his eyes and turn from the sight of his father's nudity. "Ah!"
The mad thudding of his heart was quickly being replaced by pounding in his skull; heaving a sigh, Bilbo waved towards his husband. "Thorin, go put on trousers. Bellie, darling, tell me what's the matter."
"Fetch my trousers, lad," he heard Thorin say quietly, followed by the padding of bare feet against stone, but Bilbo's attention was focused again on his distraught daughter.
"Belladonna," Bilbo prompted again, sharper, and earned a great, watery sob for his trouble.
"I can't," his daughter wailed, shoulders shuddering. "Papa, I don't— oh, Papa, why—"
Before he could press for even a sliver of clarity, Bilbo found himself with an armload of tearful tween, clinging and burying her face against his neck.
"Hush, hush now, sweet pea, hush—" Cradling the back of her head, Bilbo reached down, intending to ease his daughter's face upward, so that he might look in her gleaming eyes, the perfect mirror of her 'adad's. The first touch of his fingertips against her jaw, however, revealed quite a surprise. "Darling, shh, look at me. Please."
With obvious reluctance and no small amount of sniffing, Belladonna slowly raised her head, revealing creamy skin gone blotchy, reddened eyes, and yes, a very obvious stubble of dark, fuzzy hair along the curve of her jaw and above the pink bow of her mouth. Schooling the shock from his expression, Bilbo cupped his hand gently over her cheek, calling up what he hoped was a soothing, supportive smile.
"Goodness, my beautiful sweet pea," he murmured, and the resulting crumpling of Belladonna's already distraught face hit him like a boot to the gut. "Bellie, darling, you are beautiful— Thorin, look at our lovely daughter."
"Aye, I see." Thorin's voice was pitched low, and Bilbo wasn't certain he had heard his husband sound so very awed in years. Perhaps not since Thorin had first held a tiny, squalling bundle in his callused hands, cradling his daughter as though she were spun from the most delicate glass and more precious than mithril. "Beautiful. The very image of your fair Aunt Dis as a lass, and she is still acclaimed from the Iron Hills to Ered Luin."
Belladonna ducked her head, tears flowing slower now, but still dampening her cheeks. It was at that moment that Frerin made his return, slipping back into the room with his eyes shaded and a pair of Thorin's trousers held out like a shield.
"Here, 'Adad," he said, and Thorin took the garment with a hum of thanks, setting his sword carefully atop Belladonna's dressing table and donning the trousers. After a moment, Frerin very cautiously lowered his hand, only to let out his own distressed holler at first sight of his younger sister.
"Is that a beard?"
"Frerin—" Bilbo warned, but was ignored. Frerin was entirely enthralled and apparently quite dismayed at his sister's whiskers, mouth hanging open and dark brows furrowed.
"Why... no, no it's not fair!" Rubbing one hand harshly over his own peach-smooth cheeks before grasping at his wild nest of hair, closing his fist around braids and corkscrewed curls, Frerin rounded on Thorin with an furious glare. "She's twenty-two, 'Adad, and hairier than Kili! And I'm still smooth as an elf's arse—"
Bilbo cleared his throat loudly, perhaps a bit stung by the subject of his son's disdain, and Frerin had the good sense to bite his lip, stuttering to a chagrined stop. "Papa, I— I didn't mean..."
Of course, this would be the way it would go; Bilbo should have expected nothing less from his peculiar sort of luck. A proud son, braided and bold, steeped in dwarven culture down to his bones, but forever an inch or two shorter than his peers, with a mop of troublesome, hobbitish curls and a naked chin. And a daughter, sweet as honey and as easygoing as any Shire-born lass, with her 'Adad's ample nose, the promise of wide shoulders and thickset hips, and now a swathe of whiskers.
Pressing one hand against his stomach, even as he brought Belladonna's head back down to rest on his shoulder, Bilbo dared to wonder what this unanticipated third would bring. Perhaps a wee little ball of frizzy beard and furry feet, hirsute as a bear cub from head to toe.
Whatever came next, Bilbo had little doubt the babe would be as joyous and adorable as his or her siblings had been, before their tween years had driven them utterly barmy.
It was worth all this fuss, he reminded himself, hugging Belladonna close as Frerin began to whisper frantically at Thorin, arms swinging in wide, dramatic gestures. He loved his children madly, ferociously, and he would never think to regret them for a single instant, even at their most challenging.
Though if this lunacy showed any signs of lasting too many more decades, cursed by confounded dwarven aging, Bilbo would not hesitate to foist the pair of them off on their formidable aunt for a season or two. Dis had been moping about a lack of grandchildren, after all.
END