That was beautifully written and utterly heartbreaking. This is one of the best fics I've read this season. Just amazing. You demonstrated Sirius's complicated psychology so clearly and it tore through me.
I loved this sentence: "He'd handled that conversation well--he sometimes felt like he was only impersonating an adult, but this time had been all right." Of course. Just perfect.
God, I love writing like this that makes everything perfectly clear without spelling it out yet has a powerful emotional impact. I feel lovely and angsty now. *loves you for this beautiful fic*