There's stories to go with certain sweets and snacks, things that Regulus tells James to make him roar with laughter, memories that James shares with Regulus that warms him all the way down to his bones.
“How did you know I was here?” Regulus asks, turning to arch an eyebrow at him.
James grins at him. “One of my many mysteries, Regulus Black. Don't I just drive you mad?”
“Have I? Are you sure?” James mutters distractedly, ducking his head to find better uses for his mouth along Regulus' jaw, inhaling sharply when Regulus hisses and tugs on his hair reflexively.
James bites his bottom lip to try stifling his grin. “Well, I have been told that my smile is blinding like the sun.”
“What fool lied to you?” Regulus asks, and James busts out laughing again, unable to help it.
Remus pauses, then he deflates. “I just—I want to know, James. Just once. If—if I could have him just once, even just for a second, I'd be—maybe I could—”
“Why?” James asks, yet again. “Why can't you—why don't you want—fuck, what's wrong with me? Regulus, just tell me what it is, what I've done, because I—I'll fix it, alright? Whatever it is, I'll fix it. I swear I will.”
“Hold onto it for me,” is Regulus' compromise, and James breaks out into that lovely, lopsided smile that he was aiming for in the first place. Merlin, but he's a beautiful, beautiful boy
It's only a moment later before James makes a soft, needy noise of encouragement and chases his mouth when Regulus dares to break away for one tiny sip of air.
“It'll feel good, I promise.”
“Oh, naughty, alright. How good?”
“Have you ever felt something so good it can only be bad?”
“You,” James breathes out, then just fucking kisses him again.
He drags his hand up from the side of Regulus' throat to splay it out along his cheek, his thumb reaching to press into his bottom lip, tenderly tugging it down and watching it bounce back up when he abruptly lets go. “Sorry, just… Your mouth is, ah, very…”
Lupin jolts and makes another choking noise, though this time, it seems to be for an entirely different reason. He stares at Sirius in dismay. “You can speak French? Could you always do that? Fucking hell, don't do that.”
That one specific event he's never forgiven himself for—telling Snape how to get past the tree. It's been two years, and it still lingers with all of them sometimes, in various ways.