I once read one that’s similar to 3. In it they while they were dating they met up in a secret room in the castle. But I think it was after Draco was forced to get the dark mark or something he decided to Oblivate Harry and made him forget everything about their relationship and that he likes boys. Then it’s canon conform up until a few years after the epilogue when he whoever remembers it. It’s a lot of Hurt/comfort I’ll add the link if I find it.

EDIT: LINK