"Mmm." But it’s not just happy that Sirius is feeling. There’s a sadness there, too, a bittersweet ache in his chest knowing they have Harry when they wouldn’t—shouldn’t—have, not if James and Lily were still here. "I don’t know." He doesn’t know how to describe it, but looking up at Remus, he’s sure that these emotions are echoed in his partner’s eyes. He leans in to kiss him softly.