This is a ridiculous sibling tiff and I've had enough...
DS1 (11) and DS(8) generally get on brilliantly. They both do a sport where DS1 has responsibility for helping younger ones.
Last nights session, DS2 was being a bit silly and made a silly comment about his brother to another little one. DS1 was livid - he felt embarrassed and I can see why he was cross but he completely overreacted. Stomping about, chucking things...full on preteen strop.
Put it down to tiredness, hormones, embarrassment...DS2 apologised & both went to bed.
This morning all seemed calm. DS2 quiet but DS1 much happier. Dropped DS1 at sports class this am and asked DS2 if he was ok. Apparently, DS1 told him this morning that he wished he was dead 
I'm fucking furious. I'm going to pick up DS1 shortly. What should I say to him?