Written as a one-shot, but may add on!
The stone was hard and cold against her back. She struggled to catch her breath as the sounds of ripping flesh and screams filled the Winterfell crypts. She closed her eyes and prayed for it to be over quickly. She forgot she wasn't alone until she looked to her left and saw Tyrion sitting beside her with an identical look of pure fear on his face. He tried to give her an encouraging smile, but she knew him better than that. She knew he was just as afraid as she was.
Suddenly she remembered Arya. Tearing her gaze away from his, she pulled the dragon-glass tagger from her cloak and studied it in her right hand, all the while aware that he never looked away from her. She looked at him again after a moment and his face broke into a nervous grin as he removed his own dagger from his doublet.
She couldn't say who did it first, but all of a sudden their hands were clasped together tightly. She squeezed and he squeezed back, both seeking comfort in this hopeless situation. She tried to be strong, to hold in her tears. Their eyes didn't leave each other's for what seemed like years. All of a sudden all of their moments flashed before her eyes.
When he defended her in the throne room.
When he ran to her when the Hound had brought her back from the riot.
When he told her they were to marry.
When he told her he wouldn't share her bed until she wished it…
She knew she couldn't say the words. Not now. But she felt the silent "I love you" on her lips anyway. She swore she saw it mirrored on his face. If we survive this… fuck alliances. She'd lived for everyone else's well-being, for everyone else's whims and wishes for long enough. If they survived this, she'd move mountains to be his.
Almost as an answer to an unasked question, he raised their joined hands and kissed her knuckles and squeezed her fingers.