The song Bilbo sings is actually a poem by an anonymous author I got from "The book of a Thousand Poems". I haven's gotten around to counting them yet, but it seems like a very accurate title.
Indeed, Bilbo did manage to keep the dwarflings in line through their packing up, and even into the beginning of the trek, however when Thorin
made the mistake of sending him out with Bofur to learn how to scout, Fili and Kili saw quite the opportunity.
It took Thorin a good minute or two to realize something was off, really only alerted by the giggles neither child was able to stifle. Apparently the two of them had somehow managed a level of hobbit stealth that had not been reached by any other than Bilbo on the journey- not even Nori could move quite that quietly- and had somehow managed to undo Thorin's braids while Kili was hiked on his shoulders and Fili was bound to his wrist with a strong, if tiny, grip.
Both braids were completely undone, and the beads nowhere to be seen. It was the height of embarrassment, and would have been a stain on his honor if it had been anyone but his nephews who took them, specifically his nephews as dwarflings, and specifically in the small company of fourteen.
As it was, it was just another mark against Thorin's inability to contain them and at this point he found he had long since given up on ordering the return of his beads or anything else they had stolen. He would get them back when Fili and Kili were good and ready, and not before.
Thorin found himself not for the first time wishing he were a hobbit- and wasn't that a thought- instead of the dwarf king he was. Only this time his main motivation was a hope of gaining whatever magic Bilbo possessed to reign over chaos incarnate.
He hadn't previously considered the idea late at night as he took watch and was woefully distracted by Bilbo's ears. Nope. Not a thing that happened.
His distraction of Bilbo's ears continued later; he had found his beads.
Oh Fili and Kili were going to get it. Was there a word for murdering your nephews? If not he was going to make one. He knew damn well that the two of them knew what an exchange of beads meant, even at their age. And because they knew, and Bilbo didn't, he was going to kill them.
It really shouldn't have surprised him, as adults they had teased him more than enough about his feelings and as dwarflings they had just the right excuse to mess with him like this. Even if they remembered when they changed back, they weren't getting off the hook that easily.
Thorin was about to stomp over to Bilbo and demand his beads back before he caught sight of his sister-sons.
Both were glaring heatedly at him, eyes narrowing when he took another tentative step towards an ignorant Bilbo.
Kili shook his head and Fili mimed a slice across his neck, he would be wise to listen to them if he wanted any peace- they were promising the big guns in retribution should he keep walking.
Thorin had a very severe internal struggle going on, the company knew what the beads meant. If he let this continue his feelings would have nowhere to hide, and the hobbit could find out. If he didn't and kept walking…
Well. Fili and Kili had never been known for their mercy. And who knew how many more days until they grew up again.
Thorin couldn't do it. Maybe it would turn out okay? If he could just convince the company to not say anything and ask for his beads back when Fili and Kili were back…
Fat chance. Well, Thorin would be damned if he ended up on the bad side of his nephew's true wrath again. Once was more than enough for even an Elf's lifetime.
If his heart was the casualty, and quite possibly the loss of a burglar, well it wasn't exactly something he wanted- feared immensely actually- but Fili and Kili were worse, and would likely make his heart and burglar casualties anyway.
It had been proven that even Dis would not dare interfere with the two of them when they truly had it out for someone. Mahal help whoever that was.
Clenching and unclenching his fists, Thorin glared right back at them but conceded to walking back to camp.
He did not see the devilish grins, nor the high five, and had he seen the resumed whisper-plotting he would have realized that this was so very far from over.
The next blow to his emotions and ego came that night when the dwarflings coerced Bilbo into singing for them (read; pleaded and stole food until he gave in) and Thorin realized that the Hobbit's voice was just as lovely as the rest of him.
Two little clouds, one summer's day,
Went flying through the sky;
They went so fast they bumped their heads,
And both began to cry.
In deference to an earlier conversation between Bilbo and the younglings, he sang a merry tune he had written for the faunts of the Shire, weaving a story with his lilting voice.
Old father Sun looked out and said:
"Oh, never mind, my dears,
I'll send my little fairy folk to dry your falling tears."
Hadn't Bilbo said something about his mother's family having fae blood? If they were sirens Thorin would believe it. Entirely entrenched in the children's tune he missed Fili and Kili glancing at him and grinning again.
One fairy came in violet,
And one wore indigo;
In blue, green, yellow, orange, red,
They made a pretty row.
Bilbo would look nice as a rainbow. Thorin thought. He was hopeless. Honestly, he knew that didn't even make sense but there the thought was, bouncing around his head.
They wiped the cloud-tears all away,
And then from out the sky,
Upon a line the sunbeams made,
They hung their gowns to dry.
Bofur ruined the moment by exclaiming, "Aye lads, every time there's a rainbow, there's a bunch of naked fairy folk runnin' about!"