The first month after Harry had been born, Sirius and Remus (and... the other one) practically lived with the Potters. The two of them were working harder than ever for the Order, picking up more shifts and taking missions that would otherwise have gone to the Potters or the Longbottoms, but when they weren’t on stakeouts or raids or fighting for their lives, they were at the Potters. They helped James and Lily figure out bath time, and changing nappies, and took shifts putting Harry back to sleep when he cried in the middle of the night. Lily joked that she should’ve known that marrying James meant marrying the lot of them, and having a baby with James meant sharing said baby too, but Sirius knew she was grateful for the help, especially as James returned to Auror duty. She spent most of her downtime sleeping and working off the baby fat, determined to get back into the field as soon as she could; after the first month, she began brewing potions for the Order and researching more defensive charms. After the first month, Remus was sent on another mission, somewhere he couldn’t say doing something he wouldn’t admit to, and Sirius missed him so badly, but at least he had Harry. Then Remus missed the full—or, more accurately, spent it somewhere without them—and there was this emptiness in Sirius, this gaping hole that only the Potters could fill, only Harry, who was just starting to learn how to smile, how to laugh, how to grab his hair.