Aware he was being watched, Sirius maintained what he hoped was unsuspicious behaviour though he remained keenly focused on the other wizard. It was almost degrading, nearly begging for food and stealing what little he could hope would go unnoticed. Sirius was a proud man, a Black family heirloom even his allegiance to anyone but couldn't change. Never had he wanted for anything, even after he had run away to the Potters' house, welcomed there as if he were their second son. Azkaban had striped him of that privilege, made him beg for meagre rations and warm water if he did not want to go without. At first, he did go without until the deep, bone-penetrating cold and the shrieking of his deranged cousin mixed with his fatigue and hunger enough to break him down.
And he had been broken.
Still recovering from that, Sirius was all too conscious of how he was perceived, struggling to cloak himself with confidence so that he didn't appear as desperate and wanting as he felt. Even now, he was too proud. Pawing the floor, Sirius looked between the offered bread and the hardwood a few times to indicate he would not eat out of someone's hands, his hunger be damned.