I don't own Harry Potter and intend no infringement.
Compatibility Mode.
Harry spent his days going between classes and the library, focusing on passing his NEWTs and defeating Voldemort. He spent his weekends holed up with teachers and Aurors, learning every skill they thought he'd need to get through the war alive. He spent his evenings with his friends, doing homework and relishing the chance to be with them, spend time with them and talk to them - they were the only ones he could really talk to.
He spent his nights thinking of gorgeous red hair, hazel eyes and delicious touches.
At first, Ginny tried to pretend they weren't teetering on the edge of a relationship, and he tried to pretend they were. Really, when his free time amounted to an hour a day to play chess with Ron, or talk with Hermione, trying to date someone he got the chance to sit down with maybe once a week probably wasn't the best plan. When she wanted to go to Hogsmeade with him he was too busy being cursed into oblivion in order to improve his shielding spells. When she wanted to go to the library with him on a study break he was too busy collapsing into bed for a five am wakeup.
When she went to bed she dreamed of messy hair and green eyes; on him, on their children, waving to her as he went to work through the floo of their lovely little house with the white picket fence and roses outside the door.
Ginny wanted romance. She wanted to go to breakfast and get a surprise flower delivery, she wanted long walks by the lake holding hands. Harry tried to oblige her, but when he had to restrict the walks to an hour, and spent the time mourning the game of chess he could be playing with her brother in the warmth of the Common Room, it became a lot less than what she wanted. It was exactly what he needed, but nothing like it.
When Harry dreamt, sometimes there was a happily ever after. On one strange occasion, there was even a child; a son who looked remarkably like his mother, only with more freckles on his nose, and a sweet, cheeky grin. Harry woke from that one crying. Most of his dreams included sex, pure and easy. It's difficult to dream about a future you know can never happen.
Ginny sometimes wondered what she was doing wrong. She didn't understand like her brother and Hermione did, that what Harry was facing wasn't made for happy endings and the perfect outcome. She tried to be understanding about his constant work, but she couldn't comprehend what he was going through, so could not know the guilt he felt whenever he sat still and did nothing.
Harry sometimes wondered what the problem was. Part of it, he knew, was that she expected more from him than he could give. Part of it was guilt, that he was leading her on when nothing could ever come of it. But at night he dreamed of red hair and freckles. He dreamed of warm smiles and warmer touches, comfort without strings and love without conditions. So he told himself he could love her, she could be what he needed. But she never could be. She never could be her brother.