Regulus can tell that Pandora is nervous about introducing him to Luna. He understands; she has made it clear that her daughter will always come first. She hasn't said it outright, but he knows that if the girl doesn't like him, their relationship of three months will be over in as much time as it takes for Pandora to say she's sorry. He doesn't blame her. He wishes that they weren't facing this kind of test this early, but he understands.
That understanding is what drives him to go to the last person he wants to go to for help: Sirius. He doesn't like admitting weakness in front of his snarky brother, but the Auror has a godson about Luna's age, so he has experience with dealing with kids. After an evening of advice that ultimately boils down to, "Just be fun and remember that kids are smarter than you think," all he can do is hope that he's ready.
He doesn't have anything against kids; he would love children of his own someday. He just hasn't been around them much. None of his friends have had any yet, and while Narcissa has a son, Regulus hasn't spoken with her much since he decided not to join the Death Eaters. So all in all, he simply hasn't had the opportunity to spend time with them.
Now, however, that is going to change – if things go well, possibly permanently. As Pandora opens the front door and he follows her into her home, it feels as if his heart is in his throat.
It is messier than he expected, but he supposes he shouldn't be surprised. Between Pandora's haphazard way of looking at the world and the stress of being a single parent, it makes sense for the house to be disorganised. Sitting in the middle of the clutter is a young girl with dirty-blonde hair and silvery eyes. Yellow and blue markers are stacked in piles next to her, and she is leaning over a coloured gameboard with moving pieces.
She looks nothing like her mother, but when she looks up at him, he can see a curious sparkle that reminds him of Pandora.
"Luna," the woman in question says, sounding hesitant, "this is my friend, Regulus. I told you about him. He would like to stay for dinner if you are comfortable with that."
Luna turns those large eyes on him, and he wonders what she's seeing – how he looks to a six-year-old. After a moment, she says in a lilting voice, "That's alright. I'm not jealous."
He frowns and glances at Pandora, but she just smiles and says, "Of course not, sweetheart."
"Do you want to be blue?" she asks her mother, gesturing to the board game in front of her.
"I might sit this one out, but I'm sure Regulus would love to play if you asked him."
"Do you want to be blue?"
"I would love to." He sits across from her. "You'll have to explain how the game works, I'm afraid. It has been a while since I've played it."
"That's okay." Luna pushes the blue markers towards him and takes the yellow ones for herself. "I don't play it the way everyone else does."
Over the next few hours, Regulus comes to appreciate just how true that is. Luna isn't a normal child; it seems that she doesn't do anything the way that anyone else does. But after getting to know her mother, Regulus would have been disappointed if she were. He likes her, as perplexing as she may be, and she seems to like him well enough as well.
When Pandora sees him to the door later that night and tells him that she and Luna both enjoyed the evening, he can honestly say that he did as well.
And two years later, the day they get married and he signs the adoption papers, Luna is their flower girl, tossing daisies and radishes out into the crowd with a blinding beam on her face.