"He caught Ginny's eye and grinned at her before remembering his promise to Ron and hurriedly striking up a conversation with Monsieur Delacour."
-Deathly Hallows, Chapter Seven- The Will of Albus Dumbledore p. 119 US version
What if Harry had forgotten his promise to Ron, for just one moment?
He Caught Ginny's eye and grinned at her. She smiled back and her brown eyes did not stray from his green, as if she were daring him to look away first. Harry couldn't look away, and rather than stare at her in front of her entire family, he indicated for her to follow him back inside the house.
He reached it first and waited for her inside the empty hallway. Within moments she was there with him, and she silently shut the door behind her, leaving the noise of the party far in the distance. For a moment they simply looked at each other before Ginny spoke.
"I know Ron is angry about the gift I gave you-"
Harry tried to interrupt her, but she continued anyway.
"-But I also know that I don't regret it."
As she looked him with her brown eyes blazing, he leaned in to kiss her once more. All he wanted for his birthday was to kiss Ginny and be with her, because it was the only thing he knew of that made him feel as if his life wasn't just full of Voldemort, but full of something worth living for.
He tangled both of his hands in her sweet smelling hair, while she pressed herself against him, using both hands to grasp the back of his neck, pulling him ever closer to her. Every nerve in his body was on fire, his mind was blind to everything but her lips, her hair, her smell…
Mrs. Weasley cleared her throat from the kitchen doorway, Harry's cake magically floating a few feet above their heads. Ginny blushed and opened the door for her mother.
"Birthday boy first" said Mrs. Weasley. She sounded stern, but the corners of her mouth were struggling to match the tone of her voice.
"Right then," Said Harry in a defeated voice as he turned away from Ginny and towards the door.
"Come along Ginny, dear." Said Mrs. Weasley pointedly.
"I'll be out in a minute mom. I'm going to grab a jumper from upstairs."
"Alright dear, but be quick."
Harry watched her disappear up the stairs, but had no choice but to lead the way out to the back garden, Mrs. Weasley and his birthday cake in tow.
As Mrs. Weasley set Harry's large, snitch shaped birthday cake onto the picnic table, Harry smiled forcedly in thanks, but snuck a look towards Ginny's bedroom window.
It was dark.
He would have given everything he owned and then some to be up there with her.