Thought I'd give a tiny update. We have been using the twist crayons more and I explained to DS why. He went along but I can see that he much prefers the regular ones. I've relaxed about the whole thing and he seemed to have noticed and has been talking about it to me himself - crayons break becuase that;s how they are, we can still use crayons that are broken, we can try to fix them with tape but they are not really fixed. A bit of parroting but more to say "I understand". He still says "fix it! fix it!" but since I am more chilled, he seemed to be taking it better. thank you all for your insight and suggestions. We do have a box now with broken crayons but he doesn't seem to care much for that concept, esp melting etc. I need to show it to him to undersand.