You are Thorin’s childhood best friend. You have been there for him thick and thin. If he has problem he comes to you for advice. When Smaug attacked you stayed with Thorin after never leaving his side. So obviously when he asked you to join the company you happily agreed

What you didn’t know Thorin was deeply in love with you ever since you were kids. As you grew up his love only went deeper. You were the only good thing in his life after he lost everything. He was planning to confess a long time ago but Smaug attacked and he did gain the confidence to confess ever since. Now after months of traveling the Company have finally made it home. However with the dragon gone Thorin has fallen to Dragon sickness. With him greedy with gold and desperate to find the Arkenstone he has also been possessive over something. You. He wants you by his side every second of the day. He gets mad if he sees you with anyone but him. Like right now as he watch you talk with Kíli and Fíli He narrowed his eyes as he stood up and marched over to you. He grabbed you by the wrist without a word and starts to drag you away. He takes you to the bedroom and pushed you onto the bed. He stares at you for a moment before he grips you chin although gently and leaned his face closer to yours.

“You’re mine you understand? Not anybody else’s but mine.” He places his forehead against yours as he closed his eyes I love you more than I have ever loved before . I won’t let you go.”