Warning: Angst, and implications and mentions of incest. No smut though.
It had never been easy being Tyrion's twin; true he was nice to everyone else, and got on especially well with Jamie, but to (Y/n) he seemed to have always been vile. He hated the fact that he had been born an imp whereas she were born "normal", as he called it. He hated to fact that she were their father's favourite, whereas he was treated like nothing more than a common bastard.
He hated the fact that everyone viewed (Y/n) as intelligent and beautiful, whereas he was treated like an ugly child. But most of all he hated that she was like the mother that neither of them had got the chance to know. (Y/n) had been born first only by a few minutes, but it was enough for the Maester's to put the blame for their mother's death on him after he was born. (Y/n) looked like their mother so much that their father protected her from anyone and anything, and had even turned down marriage proposals for her, to make sure that she remained with him.
Tyrion seemed to believe that (Y/n) had been given everything and he nothing, apart from scorn and hatred.
Despite how mean he had been to (Y/n) as they had grown, deep down she loved him, the two were both so much alike; always with their noses in books, sharp of wit and able to speak about any subject with knowledge and enthusiasm.
She would always come to his defence when others tried to tease or bully him, and much to their father's and older sister's annoyance (Y/n) had even put herself in danger on more than one occasion to protect him. He of course had never appreciated her efforts, saying that he didn't need her help and that she was in fact only making things worse as he would be punished by their father for allowing her to be exposed to danger.
One day as (Y/n) walked through the gardens she had come across a number of guards pushing her brother around, having no respect for his title or the fact that he was a Lannister. She knew she should probably turn around and leave, let Tyrion sort things out for himself, but when she saw one of the guards hit him, her blood began to boil.
A small cough alerted the guards to the fact that the old lions favourite cub was behind them, and despite (Y/n)'s tender years they knew that the lioness could roar.
"How dare you touch my brother; who do you think you are to lay your hands on a Lannister?" (Y/n) growled at the men.
The guards, as well as her brother looked at (Y/n) in shock; she were not known to raise her voice often, usually she was sweet and kind, with a soft voice and a gentle demeanour. But as her beloved brother lay on the floor nursing a bright red cheek and a busted lip, she had seen blood.
"You can be sure that I will inform my father of what happened here, and you will all be punished for harming my brother."
One of the guards who had too much balls, or too few braincells let out a small chuckle.
"With all due respect milady, we all know of your father's contempt for the imp. I don't believe that lord Tywin will do anything."
A sweet smile came to (Y/n)'s face as she walked up to the man; when they were only inches apart, (Y/n)'s knee came up and went straight into the guards crotch, causing him to fall to his knees, his hands cradling his probably bruised manhood.
"And if you know my father, you will know that he will do anything I ask him to do, and I am going to make sure that all of you receive the relevant punishment for what you have done. Now I suggest you all leave before I get really angry." (Y/n) said to the men, as they quickly helped their friend to his feet and rushed off back into the keep.
She looked down at Tyrion who was still on the floor, offering him her hand to help him up.
"I don't need your help (Y/n)." He said knocking his sister's hand away and getting to his feet.
"Why do you always do this? They would have got bored eventually and they would have left me alone, now because of you, father will be involved and the whole situation will be ten times worse. I'll be punished, and you will be sat happily in your ivory tower, protected by father and Cersei, and loved by everyone." Tyrion huffed, as he rose to his full height and puffed out his chest.
That was it, after all the years (Y/n) had had to listen to him berate her for something that wasn't her fault, she had finally had enough.
"THAT'S IT! I AM NOT GOING TO TAKE YOUR ABUSE ANYMORE TYRION. I'M NOT TO BLAME FOR THE FACT THAT YOU ARE A DWARF, OR THAT FATHER DOESN'T LIKE YOU, OR THAT PEOPLE DON'T TAKE YOU SERIOUSLY, OR THAT I LOOK LIKE MOTHER. I HAVE LOVED YOU DESPITE EVERYTHING YOU HAVE DONE, BUT THAT ENDS NOW. YOU ARE NO LONGER MY BROTHER TYRION LANNISTER!"(Y/n) scream at him, loud enough so that the whole of Kings landing could hear her pain.
(Y/n) turned and walk away leaving her brother behind, shell shocked and dumbfounded.
Tyrion sat down on a bench, still nursing his bruised cheek; but now feeling emptier than he had ever felt in his life. It wasn't that he didn't love his sister, quite the opposite was true. The real fact was that he loved her too much; he loved her with every fibre of his being and wanted to be with her in every sense of the word. He felt guilty and sick, he knew that he should not be having thoughts or feelings like this, but no matter what he did or said, they would never leave him.
His obsession had begun years ago. It had been a stifling day in Kings landing, nowhere was safe from the heat, and he had been too warm to even indulge in his usual passion for reading; and he had tried to find a cool spot anywhere, but to no avail. He knew that the only place that would offer him any respite was his sister's chambers. Hers was always the coolest room when the temperatures soared, and the warmest when they plummeted.
Knocking at her door, he heard her sweet voice bidding him enter; he slipped through the door and felt the coolness of the room kiss his overheated skin. It was then he saw her, she was standing there before him in a simple see through shift; a beautiful smile on her face as she saw her beloved brother. Every inch of her body was perfection, every curve, every dip of her maturing body sent shockwaves through him. Despite the coolness of the surroundings, his body once again began to overheat; thoughts of what his body wanted to do with hers blurred his mind. Every one of his dark thoughts, every one of his dark desires came to the surface; he was desperate to touch her, kiss her, feel himself inside her.
As she walked towards him to pull him into an embrace, he pushed her away, he could see the hurt in her eyes, but he believed that it was the only way, the only way to protect them both. Since then he had pushed her away both physically and metaphorically; he had been cruel, vile; he had blamed her for everything, hoping that one day she would no longer care about him, and now after all these years his wish had come true. And now he felt empty, alone and worthless; the one person that truly loved him for who he was, was no longer there.
It had been weeks since the two twins had seen one another, (Y/n) had done everything she could to avoid Tyrion, only telling Jaime what had happened when he had seen the change in both of them and had confronted her. He had primarily been concerned for Tyrion, he had never seen his young brother so miserable, and when he had seen her, his worry had only grown.
But today was the twins nameday, and (Y/n) knew that there was no way that she would be able to avoid Tyrion. As her handmaidens prepared her for the celebrations, she couldn't help but think about him, about that day; it saddened her to know that the one person that was closest to her, the one person she truly loved, hated her. She wiped away the single tear that trickled slowly down her cheek. She stiffened her resolve, she would not let Tyrion ruin her day, she would enjoy it despite him.
As she got to the hall the celebrations were underway, she caught sight of Tyrion sitting in a corner gulping down a goblet of wine and decided whatever he could do she could do better, as she reached for her first drink.
The night became a blur as one dance turned into two, then into three as one goblet of wine turned into five and then six. She had danced and drank and forgotten about her brother, that was until she nearly fell over him.
"Oh, look who it is. Tyrion something isn't it?" (Y/n) said with a slight giggle, the wine clouding her mind a little.
"(Y/n), I think you have had enough to drink; I think I should take you back to your chambers." Tyrion said, holding out his hand for her to take.
"And I think you should leave me alone and let me enjoy my name day." She said, pocking him in the shoulder, almost pushing him over.
"(Y/n), please let me take you." Tyrion pleaded, holding out his hand once again.
(Y/n) stared into his eyes, the look of disdain that she was used to seeing had gone, and all she saw was a look of love.
Tentatively she took his hand and allowed him to lead her out of the party and back to her rooms. The journey had been quiet, neither of them saying a word; all she felt was his hand on the small of her back, leading her all the way. Once in her chambers the pair sat on her bed, Tyrion resting his hand on her thigh.
"(Y/n), I'm sorry, I'm sorry for everything I ever said or did to hurt you; but I had a reason, and I believed it was a good one, but now I'm not so sure." Tyrion whispered.
He looked up and saw the tears in her eyes. "Why Tyrion, why would you do this to me? I love you."
Tyrion reached up his hand, placing it around her neck and pulling her down to him. He looked at her startled eyes for a moment before placing his lips onto hers. He had expected her to move away, to slap his face, but instead she deepened the kiss; reaching her arms around him to pull him closer.
"I did it because I love you, and I want nothing more than to be with you, to be connected to you body and soul." He said, as they moved apart.
"Tyrion, why didn't you tell me? I love you; I've always loved you. I want to be with you in anyway you want."
(Y/n) stood up and undid the laces on her dress, allowing the fabric to pool around her feet as she stood in front of him, taking his hands and placing them on her warm supple skin.
"Love me Tyrion, in any way you want, but just love me."
She slipped under the furs on her bed as he undressed; and as the two became one, they both knew that nothing would ever be the same and that neither of them would let the other go.