When Kili leaves the camp, he thinks he's the only one awake...he's wrong.
Bilbo is near a tree smoking his pipe while looking at the stars. He was concerned when the young dwarf ran into the woods. The Hobbit followed him, quiet as a mouse, hoping he could help Kili if he had fallen ill.
He found him sitting on a fallen tree, trousers open, jerking his hard cock gently.
Bilbo's eyes went wide, mouth fallen open. He hadn't been intending to invade on this private moment!
He was about to turn and leave but Fili was joining Kili and Bilbo was stuck, curiosity holding him in place.
"Starting without me?"
"You were taking too long."
Fili caught Kili's lips in a kiss. "Bofur woke from a nightmare, I couldn't leave him until he was sure he was fine."
Kili smiled fondly at the blond. "You're a good man."
They kissed again and Fili's hand took his place. The younger of the two thrust up and cried out. Fili grinned and jerked harder.
"Oh, you like that, little brother?"
"Yes! Fili yes!" He panted.
The blond sank to his knees and Kili's hands found his brothers hair easily, a well practiced move. Fili's tongue teased before his lips enveloped Kili's cock completely.
The breath was caught in Bilbo's throat and his pants felt awfully tight in the front. He knew it was wrong, so wrong to be watching these two Dwarve's go at it, even more wrong to be getting excited over it...but he couldn't stop watching.
They stripped their clothes off and Bilbo forgot how to breathe. Their bodies were beautiful, well muscled from training since they were children. Fili's back flexed when he picked Kili up to have his legs around him before lying on the ground. The older brother kissed down Kili's body, lower, lower...
Oh, he was using his tongue on Kili...in places Bilbo never even dreamed of! Yet there were Fili and Kili doing. The younger arching his back, pushing down onto Fili's tongue, breathlessly begging for more.
When Fili sat up and positioned his cock at Kili's entrance, there was a snap behind Bilbo. He spun around, tripped over his feet, and fell flat on his face.
"What are you doing out here, halfling?"
He looked up to see Thorin stairing at him. "I-uh-I well, I needed some air."
A long moan from Kili made Bilbo blush and Thorin laugh quietly.
"Ah, spying on my nephews?"
"I hadn't intended to spy!" He defended himself, finally moving to stand. "I saw Kili leave and I was worried that he was ill...but...he isn't." He rubbed the back of his neck. "I'll just be going."
Thorins eyes fell to the front of Bilbo's pants. "Are you sure?"
Thorin grinned at the Hobbit's stutter. "Are you sure you want to leave? You seem to have something you need to...take care of."
"N-no, no "I'm fine." He went to walk back to the camp but Thorin grabbed his arm.
"Would you like help?"
Bilbo stared, mouth hanging open, not sure that he heard the Dwarf correctly. "I'm sorry...what?"
"I'm asking to help you."
"Why not? Could you not use the physical attention?"
Bilbo was utterly confused, but when Fili and Kili both cried out, he lost his ability to care.
Thorin moved closer with slow and measured steps. Bilbos mouth went dry and his heart hammered in his chest. When Thorin was right on top of him, arms around the Hobbit's shaking form...Bilbo's legs gave out.
Thorin caught him easily. He studdied the halfling for a moment. "If you do not want to do this, tell me."
Bilbo took a second to consider it. He could easily walk back to the camp, go to sleep, and forget all of this ever happened, but that didn't sit well with him, he couldn't even remember the last time he was touched by a hand that wasn't his own.
He found himself shaking his head and mumbling 'don't stop' over and over again. Thorin chuckled at him, he did sound a bit wanton, even to his own ears.
The Dwarf moved behind him, pulling Bilbo's back flush to his chest. His hands moved down to the Hobbit's hips, pulling his rear right up against his aching cock. Bilbo closed his eyes, the sensations almost too much.
"Open your eyes, watch them." Thorin demanded.
Bilbo did. Fili pounded into Kili, the younger of the two tugging Fili's braids.
Thorins hand slid down, cupping Bilbo's erection through his pants. "Watching them excites you. Why?"