Sharon, at the risk of being labled permissive, can I ask what the heck the big deal is? Get thee to a Home Depot (or Lowes) and visit the paint section. A can of stain-block spray primer has to be less than $5. It can’t possibly take more than 5 minutes to use up the whole can, and did he really use that much?

I’m of the opinion that school is highly over-rated, and that children are over-educated (and improperly educated at that.) I’d let him walk on the painting, but then again, I’d let him walk on the school day as well.