The Months of Grimmauld Place
The first month Remus lived at 12 Grimmauld Place, he wouldn't even listen when Sirius made the suggestion.
The second month he listened to the suggestion, but only because Sirius put Remus into a chair and then stood in front of him while he talked. There was a tension to Sirius, almost a mania, that made Remus wonder if the suggestion was really supposed to benefit him after all, or if it was because Sirius wanted it. Either way, Remus' answer was still no, and he still wouldn't discuss it. Eventually Sirius threw his hands up and let Remus out of the chair and they went on with things, but they were stiff with each other for a few days.
The third month Sirius managed to get under Remus' skin, so he took the bait and they had a blazing row over it. Remus said Grimmauld Place was the headquarters for the Order of the Phoenix and he couldn't possibly be as selfish as Sirius was suggesting. Sirius said it was his damn house, and he could do what he wanted. Remus said it was much too dangerous, as someone could come to headquarters in the middle of the night. Sirius said they could warn people. Remus said he didn't care to have the whole Order think he was behaving so incredibly selfishly as to take over headquarters for his personal use. Sirius said he could do with acting selfish once in awhile, and did he have to keep telling Remus that it was Sirius' house and he ought to be able to have some control over it. Remus said he didn't want to remind everyone, even though he knew they all knew, he didn't want to shove it in everyone's faces every month that he was a werewolf. Sirius said he couldn't leave the house, that even Remus wasn't there most of the time, and he was lonely, and this was something he could do, and didn't Remus miss...?
Sirius left the room at that point. There were too many emotions surfacing. Later, in the quiet hours of the evening, Remus came to him and said yes, I miss it. But the Order. And Sirius said, hang the Order. It's my house.
From month four onward, an extra set of protective charms were placed on the house during the night of the full moon. A note was also placed on the door: "This house set aside for the use of Messrs Padfoot and Moony. Those not wishing to contract lycanthropy will kindly return after sunrise."
The furniture survived relatively well, all things considered, although the stairs got a tremendous amount of wear as the wolf and dog chased each other up and down the floors. Mrs. Black's portrait acquired claw marks, which both men adamantly claimed credit for despite there only being one set of marks. Sirius was never happier than on the day after the full moon, and though Remus could never truly be said to be happy on that day, he looked considerably healthier than anyone could remember seeing him.
The month of Sirius' death, the sign did not appear on the door of 12 Grimmauld Place. There was no sound of thundering paws from within, no sharp bark of canine laughter. But somewhere not too far away, a solitary wolf could be heard howling and keening to the wind.