Hi. My DS is 7. He is popular and gets on well at school etc. But he really struggles with not winning or being "best".
For example, shouting at younger team-mates at football class for being "crap" when other team scored-note,he is not exactly Wayne Rooney either! 
Coming home from other lessons,e.g., tennis in foul humour/teary because someone else did really well.
Sobbing and spending half an hour screaming about best friend because friends premiership footie team beat his team!
Today he had a meltdown at home time, because he found out someone else won a homework comp! He came second! 
We have always stressed the importance of taking part that counts, being part of a team etc...being a bad/good loser....but he is getting worse!
Has anyone any experience of this? Any books or anything to help?
Much appreciated.