Greed had no idea how to take care of Lust. It wasn't a concept he understood when he was usually either fucking her or whining. He had attempted to take care of a mortal girl before but he was on his own then, things became confusing. Lust in this depressed state was unusual. It was awkward because usually she took her and Glutt under her wing.
He'd simply needed a breather. Taking the opportunity to get some food (and he'd be hardpressed to get any for anyone else) Greed jumped in for a five-fingered discount. Glutt wasn't the only one who could stack away some food. He hadn't even realized as he hauled off with his food that his wallet (or someone else's) had dropped out of his pocket. It wasn't the only wallet he had shoved in his pockets.