Okay so there are not enough headcanons about healthy poly ships, so imagine this:
Draco in eighth year wanting to reconcile with everyone he’s hurt and try to do better. He ends up getting along extremely well with Ginny, bonding over quidditch and having deep conversations about being forced to do things for Voldemort they didn’t want to do.
And of course, they discuss Harry. Ginny talks about how she and Harry haven’t really kissed since that last time after the battle, even though they’re still close. Draco talks about how he’s always been drawn to Harry, and how he realized everything he felt for him in seventh year.
Ginny sighs wistfully. “I always thought you had a better chance with him than I did; after all, he was awfully obsessed with you in sixth year.”
Draco looks at her incredulously. “He thought I was a bloody death eater- I mean, I was, but that’s not- What I mean is, he’s so obviously straight!”
Ginny raises an eyebrow. “And I became pretty sure he was actually gay.”
Ginny, being the Gryffindor that she is, decides to ask Harry outright, dragging a reluctant Draco along by the ear.
Harry stares at them for a moment. “Really, Gin? I thought you knew I was bi.”
He stops and glances back and forth between Ginny and Draco, before grinning giving Draco an appraising look.
“Although, I guess I haven’t told you yet that I’m also polyamorous.”
And thus begins the closest and best relationship that could ever possibly be.
I mean, imagine all three of them screaming about quidditch together, two of them often ganging up against the third in support of specific teams.
Ginny begins playing for the Holyhead Harpies and Harry and Draco show up to every match, embarrassingly decked out in team merchandise, cheering so hard that Ginny blushes during her games.
Imagine Harry introducing Ginny and Draco to muggle things they’ve never seen before, and he finds them snuggled up watching the telly or playing muggle board games when he gets back from his Auror training.
Imagine Draco helping Harry and Ginny with wizarding fashion and etiquette, and them bursting into parties and dinners all linked in arms with the most impressively stylish robes, causing endless gossip to spread around the room while they all three take turns dancing together.
They live long and happy lives, with James, Al, Scorpius, Lily, and more often than not, Teddy; and are the wizarding world’s most legendary romance.