If your brother was a difficult sibling he was, in all likelihood a difficult parent too. Your nephew has made a kind request, and as others have said, the funeral is for the living, not for the dead, and maybe by getting to know your nephew better you will both be able to understand just why your brother was how he was. Your brother has not expressly forbidden you to attend. Also, your absence could be interpreted by other family members as you being the 'difficult' party, although this may not bother you of course. You only have one opportunity to attend, and in your position, I would go.
Fruit flies - help needed please.
Army horses loose on London streets
Have any of you got all electric cars? Pros and cons please.