Man that is a tough one.  I feel the same as you.  Nothing gets under my skin more than what you just described. 

It is easy to give the advice, but it is darn hard to follow. 

So here is my advice. 

Kill them with love.  Just let them have all the glory because it really does not matter. 

Man, my evil ego says other wise, but I believe what I suggested here is the best way. 

I believe it really takes a bigger man to let the big shot be a big shot than it is to change him.  We both know he is not likely to change.  I know it sounds like I have already given up on the big shot changing, but 99% of the time it is true.  I know I need to "get along with people".  You know the good Book has a letter telling the new Christians to stop their arguing.  I think they were arguing about who was baptized by who,ect. 

So I think God has one big test lay before you. 

Can you stand aside and let the big shot have all the glory, no matter who thought up the celebration?

We all are sinner, just in different ways. 

And yes you need to tell the big shot now if you are not going to help or do the work.  You will not gain a thing by putting him in a bad position.  Prob. loose more than you can imagine if you do so. 

So there is my 2 cents.