She's a light sleeper.
Every time he slips into bed beside her, she wakes. He doesn't wrap his arms around her, doesn't press his bare chest against her back. But his body heat warms her. She never turns around when he comes. Wonders if he knows that he wakes her every single time. Wonders if he would care if he knew.
Sometimes he twitches. He has nightmares every night he's with her—she watches his face when she's sure he's fast asleep, and always turns back before he wakes. His pupils move back and forth behind his eyes, his lips purse together; his breathing will quicken, then slow. She knows what the dreams are of—Sephiroth. Aerith. Not necessarily in that order. She looks at him sadly.
Oh, Cloud.
Sometimes she cries. When she's turned away, because if he ever awoke during—no, it just would not do. She is careful that her sobs don't wake him; he needs his rest, even if it's not very restful. She cries herself to sleep, with his sleeping form beside her.
And when she awakens, he is gone.
And she cries more.