My yf and I were out at our usual hang out place last week and I let him go hungry. We had woken up late that day and planned on just having lunch while we were out. He had money for food for both of us from his father. He spent money set aside for food on a few little toys instead of food. I have talked to him about his spending habits many times but was not right next to him when he spent his money this time. When I mentioned it to him he said he did not think he would get hungry and spent the rest on a cookie. It was not that it did not occur to him but that he did not think he would get hungry until his dad came to get him at 10pm. There is little else to say to him about his spending habits at that point so a few hours later I bought myself some food and let him go hungry. He seemed to have actually learned something, I hope so.