He looks at her and she's so beautiful and he wants to be with her so much but he can't because she won't even though he can tell she wants to. He likes her and she likes him but just because he went out a few times with her best friend in fourth year she is pretending and she won't let it happen even though sometimes when they talk she leans in close and he can feel her warmth. And he knows that if he will ask she would deny and say she was cold, and she would be mad, and she wouldn't speak to him for a few days, and only whisper with Lavender in the common room and he'd stare and he'd hate it and she would look at him and whisper something in Lavender's ear and they'd both giggle like they sometimes do.
So he doesn't ask. He just leans close and he can smell her and he doesn't want to fall, so he takes her hand. And she doesn't pull away.