Fleur and Harry get together as a couple during the Triwizard Tournament, but Harry wants no one to know, as in Dumbledore, Voldemort, his friends, etc. To everyone they appear to be friends, who after the end of the tournament seemed to have cut all contact. But what they do not know is, that every few weeks, a dark feathered bird would fly over the Privet drive, and drop a photograph to Harry. A photograph of his love, wearing various shirts, with messages like: I Love You, or You are my Life.
Harry can't stand this, so he hatches up a desperate plan. Fleur enters a "relationship" with Harry's only confidant, and older brother figure, Bill Weasley. When he meets her again at the Burrow, he wants to say so many things, but, one look is enough. She understands. She always understood. So they continue on, together, but separate, sneaking in silent conversations by making eye contact.
Bill is forced to be more convincing, so he and Fleur exchange an occasional peck. Harry wants to be angry, but he can't be. This was his plan. But that night, the photo he receives is... different. The shirt is more form fitting. And the curves are much more exposed.
They manage to fool everyone, but not without risks and sacrifices. But for every time Bill is forced to make a step further to convince everyone that he and Fleur are in love, the photos Harry receives afterward get more risque.
The last photo Harry receives is after a Christmas party, where "drunk" Bill and Fleur are "caught" making out in the kitchen, and he's groping her. The photo is Fleur, fully exposed, with fiery words above her.
I want you.
This is an expansion of my previous prompt, but I had a train of thought how magical photos are neat, and how much they could mean to someone.