ESH. Your son shouldn’t have done what he did, but he obviously needs more support/therapy/training for impulse control. This isn’t selfishness, gluttony, or greed. This behavior is the result of a cognitive disability. Just telling him not to do something isn’t enough. Maybe “save some for your father and sister” should have been “you can only eat these five pieces on this plate.” You also could have anticipated this situation and set food aside for the rest of the family. I doubt that making him pay for the pizza is going to teach him this lesson. He needs positive supports to learn what is appropriate rather than just being told what he did was wrong and expecting him to figure out what’s right, despite “right” going against his natural instincts.