This is a Casifer imagine to satisfy all your Casifer needs, enjoy!

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You eyed him intently, you were still not fully comfortable with him being around. You were standing at the far end of the Bunker library, peeking through a gap of books to find Cas... correction, Lucifer sitting and reading case files from the storage room.

He's agreed to help with defeating the Darkness, but he's a stubborn ass about freeing up Novak's vessel and ultimately releasing Castiel form being trapped.

You liked Cas... and you didn't like Lucifer.

"Hey sugar," Dean greeted and walked over to you, raising his eyebrows when he saw your head looking through the opening between two books, "Somebody's being a spy."

You held his arm and shushed him quickly, "I'm watching him, he may do something fishy."

Dean placed his arms on the library shelf, on either side of you, and matched your view, looking at Lucifer as well. He kissed your neck a little harder than usual and you grabbed his hands.

"D-Dean stop it, I don't want h-him to s-see," You managed to say with effort but he disobeyed and pulled you to the corner wall. He glanced at Lucifer and then turned to you.

He put his finger on his lips and shushed you. "Don't make a sound no matter how badly you want to, and he won't find out," He whispered gruffly.

You didn't like this at all, even though you wanted it badly. You didn't want the stranger in the room to see and know anything, you despise his attitude. He doesn't know where to draw the line.

"Dean don't, ple-"

He moved closer to you, grinding his hips into yours and you arched your back. "F!@#..." You moaned breathily then grabbed his arms and dug your nails into his skin.

"D-Dean move please," You pleaded breathlessly, "We have the night alright?"

"Why?" He tugged on your hair and then kissed your neck. "DEAN!" You exclai-

He covered your mouth and you both stood completely still. You stood up on your toes and looked over the book shelf to see if your voice stirred Lucifer's attention.

Thankfully it didn't.

You wiggled yourself out of Dean's strong hold then pushed him aside lightly, walking back to the shelf you were sorting out.

"[y/n] come on, what's wrong?" He asked and wanted to kiss your cheek but you loved away and furrowed your eyebrows.

"I don't want you near me while he's around please," You said snarkly, "We can do whatever we want in the bedroom but if we're outside then you're not my boyfriend."

He frowned, he looked a little hurt. You sighed, then picked two books and started walking to an empty table.

He grabbed your arm and twirled you around, placing his lips on yours for a much longer time than you'd like.

He smirked, "Fine sweetheart, but you have to make it up to me then, obey whatever I say."

You gulped and darted your eyes to Lucifer, who was watching you until you looked at him, then turned away immediately.

"O-Okay... now get out of here," You said then clenched your jaw. Dean rolled his eyes and walked out of the library after taking the beer bottle he had brought with him.

You stepped towards Lucifer slowly, dreading the fact that at any moment he would comment about-

"How long have you and Dean been together?" He asked, putting his hands together and looking at you with what seemed like a genuine smile.

You didn't want to answer but you felt that it would lead to him pestering you more.

"Um... a little more than a year," You answered flatly then went back to reading your book.

He nodded then squinted his eyes a little, "He really seems to love you a lot."

"Y-Yeah he does."

"And you guys have a good time I guess," He said, "He seems like someone enjoyable-"

"Lucifer stop talking. I have no interest in making small talk with you out of all beings so you continue your work and I'll continue mine," You snapped at him and he raised an eyebrow.

"Fiesty... sorry, gosh."

He went back to his work and silence fell upon the Bunker... at least for five minutes, till he spoke again.

"You could seriously do better."

You looked up, a mixture of anger and confusion at his statement. "What?" You watched him with disbelief.

"I'm just saying that you can find someone who's worth your time more," He commented, "Dean just... isn't the one for you."

You'd scoffed and he rolled his eyes. "Oh I'm sorry, since when are you the local matchmaker? You have a dating show or something?" You mocked the fell serious, "I don't give a crap about your opinion. Dean and I are just fine, we love each other."

"Then why are you so nervous about him being affectionate to you in front of people?"

"People? YOU aren't 'people' Lucifer!" You said with rage, "You don't matter to me at all, you are insignificant! Quit having an opinion and work towards solving the main problem that is the Darkness."

He squinted at you, "That doesn't answer my quest-"

"DON'T PUSH IT!" You shouted and he huffed.

He paused a for a while then spoke up again, he was REALLY testing your patience.

"But if you look at me for example, I could be someone who would make you feel like a queen," He said and you glared at him, immediately standing up.

"Alright what the hell is your problem?! You suddenly don't understand English? STOP POKING INTO MY PERSONAL LIFE ASSHOLE!" You raged out in the loudest voice modulation you could.

You laughed mockingly and crossed your arms, "Do you really think I would ever think about being with YOU? I hate you, I hate your guts and your attitude, I hate the way you talk and I hate the choices you make. I HATE YOU."

"But Castiel loves you."

You were walking out of the library to complain to Dean or let some steam off, but stopped when he spoke.

"W-What..."

"He loves you, I can't seem to block that part of him out of my mind," He sat back in his seat, "I'm telling the truth, cross my heart." He did the gesture and looked at you with genuinity.

"You're lying."

"And that's normal for you to think, given the... sad sentiment you have towards me but it's the whole truth," He said, "He really admires you and even right now he's watching you."

Lucifer chuckled, "Castiel loves how you're hating me right now. He's um... happy with that."

You stepped towards him and commanded sternly, "Tell me the truth."

He rolled his eyes and groaned in frustration, "Oh my-I'm telling you the truth [y/n]!"

You mentally spat at him and shrugged your shoulder, "I don't believe you." You turned around and started walking out of the-

"I-It's true [y/n], he's telling the truth."

The tone of voice suddenly changed,it wasn't Lucifer anymore... You recognised it.

You turned back quickly, "Castiel?" He nodded his head and stepped to you, "It's wrong for me to say this because you're not available b-but I... l-love you."

You hugged him, you wanted to kiss him badly but you held back from it. You still love Dean deeply, like you never have ever before.

"Cas I'm so sorry, you must be crushed because I'm with-"

"I'm not feeling like that at all, Dean is a supportive and loving person and I'm so happy for you," He said, shakily, "I don't think I-I could e-e-ever..."

He his head snapped forward, it wasn't Cas in control anymore.

"See? I'm not that evil," He said with a smirk plastered on his lips and you shuddered, pulling yourself away from him swiftly.

You continued to glare at him till you turned away and walked towards Dean, to tell him about all that you went through right now.

Even that Cas was in love with you...