Anyone that you just simply refuse to play music with, no matter how talented they are ? For me there is this one guy...Talented KB player and singer, with very good connections that go pretty far up the jam band scene on the national level...Problem is, the guy is a total and complete douche. I really don't want to get into the reasons why, I'll just say he is the largest douchebag Ive ever met, and there are many people other than me that share that sentiment. Unfortunately I have such a negative opinion of this guy I cannot even bring myself to share the same stage with him..He was invited to sit in with a band I was playing with recently by that bands KB player and I made it clear that there is simply no way that I would be able to play music with him. I know it seems petty and probably mental, but there is something that just brings out some pretty negative vibes from me about this person.