Any errors are mine, please tall me if you spot any.
One
The first time Thorin sees Bilbo dancing it's with Ori. Young Ori Ri's son who is so eager to learn about everything and anything. Thorin is sure that once Erebor is reclaimed and restored to its former glory, Ori will be a celebrated Dwarven scholar. Ballin had noted to Thorin once that Ori would become obsessed with a subject and learn everything he could about it. Hobbits, and Bilbo specifically, seem to have become Ori's latest obsession. As Thorin watched Bilbo patiently try and teach Ori some kind of complicated footwork, he noted to himself that not only was Bilbo very light on his feet but that he would have to make sure Ori didn't learn to much about Hobbits with attractive hair covered feet and curls the color of glowing gold.
Two
The second time Thorin observes Bilbo dancing, he's dancing with Bofur in Beorns living room. Thorin suddenly finds himself finding faults he hadn't seen before in the minor/toy maker. From the way his stupid braids hung to how easy he smiled as he twirled Bilbo around.
Three
The third time Thorin catches Bilbo dancing it's the night before they leave Lake Town for the mountain. Bilbo is dancing with anyone willing like some kind of dancing doxi. Thorin realizes how unjust to Bilbo his thought are, but he just can't seem to stop thinking them. So instead of doing what he really wanted to like telling Bilbo he must not dance with anyone else and must stay by Thorins side at all times while in Lake Town, he sulks in a darkened corner by himself.
Four
The fourth time Thorin watches Bilbo dancing it's with Fili and Kili on a pile of gold. Smaug had been defeated, and with the exception of the Arkenstone the mountain was theirs. But still Bilbo doesn't look happy, in fact Bilbo looks fairly morose compared to the others. Still Thorin feels more secure than he has at any other time on the journey and he thinks about asking Bilbo to dance. Unfortunately in between one blink and the next Bilbo disappears behind a hill of gold.
Five
The fifth time Thorin sees Bilbo dancing it's at the end of his arm as he dances on air. There is a stark fear in Bilbos eyes as his feet dance wildly trying to find purchase. Thorin can't find it in himself to care, nor does he find the desire within himself to ask Bilbo to dance any longer. When Gandalf rides out from the midst of Thorins enemy's he is immediately shuffled in Thorins mind from Helper to Traitor. When he calls for Thorin to let Bilbo go Thorin almost dropped him right then and there. Instead Thorin lets the beardless traitor go on a rope.
And The One Time Bilbo Dances With Thorin
Bilbo had saved the line of Durin the day of the Battle of Five Army's. Bilbo had granted the dwarves with true forgiveness. Bilbo had left two days after Kili woke from his coma. Bilbo rarely answers letters from the company and even more rarely from Thorin. A year from the day he left Bilbo shows up on the Erebors doorstep. A year after that and he was desperately seeking to teach Thorin the dance steps for their engagement ball. Thorin always thought Dwarven dances were complicated but the much freer steps of the Hobbit way of dancing was proving much harder. Three months later and Thorin and Bilbo were taking turns leading each other in the dances of their peoples at their wedding feast.