Sirius hears Harry’s breath catch in excitement; gifts, for the boy, have been a new wonder—he received so many on his birthday (and this was after Remus had curbed Sirius’ gift-buying) that the boy had positively broken down in disbelief. Remus had, quite rightly so, been a bit afraid that Sirius would spoil his godson, but it soon became clear that they would have to work hard to have him accept gifts as such, and not as bribes or something he would later owe them. Sirius has risen to the challenge with much enthusiasm.