I too have had a similar experience with a 7 year old girl a few years ago. She had to run upstairs from the playroom 'to check if she remembered to bring something home from school in her backpack'. It happened frequently and I noticed many things go missing, which of course turned ip in her backpack. Spoke to mom who chalked it up to 'normal' 7 year old behavior and jealousy. I wish I'd have terminated immediately in my experience because there were also other behavioral issues but that's a whole other story. I'd say talk to parents let them know how you feel, put special toys away and impose serious consequences should this boy steal again. Totally unacceptable. I'd begin advertising if I was in a similar situation to find a replacement family. I know it's hard starting from scratch with a new family but its even harder trying to watch a 7 year old constantly trying to thwart his stealing. Good luck