I know this took forever but it was redone multiple times. The songs mentioned: 'something about luck being a lady' is A Good Run of Bad Luck by Clint Black. 'It's your fucking nightmare' is Nightmare by Avenged Sevenfold, and because I found it funny, It's Getting Hot In Here by Nelly. I like the idea of Lucifer like all kinds of music verses only liking a certain genre (death metal being something people might think he listens to.)
Yes I am aware how short this is.

Chapter 11 Doubt

Castiel was not amused. He had heard what Gabriel had said about Lucifer using Sam and he could not disagree more. Lucifer may not be the best influence but from what he could tell Sam and Lucifer were happy together. Isn't that what matters? That they are happy together?

Why was it so important to Gabriel that Sam has doubt about Lucifer? Millions of years could change anyone. More importantly, one person could change your world just as effectively. Look at what Dean had done to him. He never would have thought that he would ever be as close to a human as he was with Dean. Why couldn't Sam be the thing that changed Lucifer for the better.

When Gabriel left the room, Castiel took his place though he stood in the doorway instead.

"Do not listen to him." Sam's head snapped up at the sound of Castiel's voice. "Do what you know to be the truth in your heart."

Sam looked to Lucifer, who smiled. "Am I what's in your heart Sam?"

"Even if it is the devil himself?" Sam asked, looking at the floor.

"It does not matter who, Sam. All that matters is that the love you feel is genuine." Having said his piece, the angel left the room, leaving Sam and Lucifer alone.

Lucifer still had a smile on his face but he was studying Sam's features.

"Can I ask you a question?" Sam asked, biting his lip.

"Of course, Sam."

"When you said you loved me," He began but Lucifer cut him off.

"I meant it Sam. I love you in a way nobody else is able to. In a way nobody can even comprehend. Why?" He crossed the room from his spot in the chair back to the couch. His grey eyes baring into Sam's as he spoke.

"Because, I think I love you too. It's strange, it's not what I felt toward Jess, it's more... something. I can't explain it." Sam wanted to look away from those intense eyes. His heart picking up it's pace. Lucifer's face was blank, missing it's usual smile.

"I can not begin to tell you how happy that makes me. To know that my feelings are returned to me is more than I could ever have hoped for." Reaching up, he grabbed the lapels of Sam's button up and pulled him in for a kiss. It was slow, and sweet, and somehow perfect.

...

Over the next few days Lucifer began disappearing for short amounts of time that slowly grew into multiple hours of being gone. If the room was quiet Sam swore he could hear something in the back of his mind that sounded vaguely like a tune.

Lucifer was gone for two days. The tune he could hear sometimes would sometimes get louder to the point he could hear a few words. Something about luck being a lady.

Castiel noticed Sam spending more and more time alone while Dean worked on the Camaro and Bobby did his business in the scrapyard. As it turned out, Gabriel had a knack for destroying vehicles and came in handy in the yard.

The angel sat beside the human at the table, a furrow between his brows. "What is wrong, Sam?" The hunter sighed and leaned back in his chair, rubbing his hands down his face.

"Lucifer's gone. I don't know where he is." Castiel nodded as if that made perfect sense.

"He is an angel, a fallen angel but an angel none the less. Perhaps he had business elsewhere?" He offered. He was not good at compassion but he was working on it. "You did say he was able to go to Hell, perhaps that is where he is now?"

"Do you think Chuck would know?" Sam asked. The angel shrugged.

"There is no harm in asking."

Sam and Castiel made their way down to the panic room where Chuck was staying. The Prophet himself was typing away at an old typewriter of Bobby's, his hands busy as he wrote what he saw in his visions.

"Hey Chuck." Sam knocked on the frame to grab the other man's attention.

Chuck turned from his work to see who it was through squinted eyes. "Oh, hey. What's up, Sam?" He turned back to his work, typing furiously as if trying to make up for the second Sam had taken from his work.

"I just wanted to know if you know where Lucifer was." He rubbed the back of his neck.

"Lucifer? Oh, yes. He is in Hell raising his army for the war." Chuck stood up from the plastic chair, stretching his arms and back before turning to face the hunter. "Hello, Castiel."

"Hello, Chuck." The Angel replied, trying to be curtious.

"What do you mean he is trying to raise his army?" Sam asked, not understanding. Why would Lucifer need an army? What would he need to fight?

"For the war with the Angels." Castiel told him. It took a minute for it to dawn on the hunter they were at war. How had he forgotten?

"And he thinks he will need an army of demons?" Sam asked, perplexed. Something just wasn't clicking in is mind. He knew that he knew the answers but for some reason they just did not want to come to him.

The melody was back, a few words coming to him from the back of his mind. "It's your fucking nightmare." And more melody. Where was it coming from?

"He expects the angels will use the entire Garrison against him." Chuck let out a sigh before taking off his glasses to clean them against his shirt.

"The Prophecy clearly states that Sam would be the one to decide what happens to him. Why would either one of them need an army?" Castiel asked, the furrow between his brows returned.

"If the Garrison takes Sam then Lucifer will need his army to take him back. He has no intention of fighting. He wants the whole thing to pass over smoothly now that Sam has confessed his love to him." He placed his glasses on top of his head before giving the man a hard look. "I know why, I just don't understand the connection you two have. I know I wont thanks to the whole," he gestured toward the heavens, "bond thing you have but I have to ask. Does it bother you that Lucifer is a guy?"

Sam raised an eyebrow. "Should it? Lucifer's vessel, Nick, is not what I find attractive about Lucifer. I love Lucifer as himself." He could not stop the grin from sneaking onto his face. "And Lucifer is not a guy, he is an angel of the Lord."

He thought he heard Castiel chuckle.

...

As the day wore on the music in his head got steadily louder. He was soon hearing whole songs as Lucifer sung them. Sam took it to mean the angel was on his way back.

He had never felt more excited. His heart pounded in his chest, and he felt something like a bubble in his chest making it hard to breathe.

"It's getting hot in here, so hot, so take off all your clothes! I am getting so hot, I'm gonna take my clothes off!" Lucifer sung happily, dancing around to stand in front of his vessel, hands gripping the hem of his shirt and slowly raising it to show his stomach. Sam couldn't help but laugh before pulling the other man in close before capturing his lips in a kiss. Having the devil in his arms made Sam feel complete. His lips against the other man's, hands exploring, the feeling of undeniable happiness. This is love. Wanting to spend the rest of his existence with Lucifer was the one thing that made him glad he was a hunter.

When they pulled away, lips swollen and out of breath, Lucifer let out a low chuckle. "Miss me?"

"Shut up." And he crashed their lips together.

...

Castiel could not help but feeling a sense of pride. His brother was happy with Sam, something he thought he would never see again. Gabriel on the other hand, stood beside him, watching the scene unfold before them with a scowl. Lucifer was a bright light against Sam, a testament to his joy. For some reason watching the two of them made him angry. He did not understand why but there was something boiling inside him.

"Rejoice brother, Lucifer has found love." Castiel said, a small smile playing on his features.

"Why? What are the chances it is real? How do we know he is not just using Sam?" Gabriel muttered.

Castiel turned his head to look at his older brother. "Why can you not just be happy that they have found love?"

"I'll believe it when all of this is over. Then we shall see who is right." With a flutter of wings, Gabriel was gone.