Please explain? I guess there is potential for conflict of interest?
Should I tell my W not go with her or should I just call her and tell the C that I don't think it's a good idea?
Well, I think it's somewhat unethical on the part of your C. Whether it may or may not be officially unethical, I'm not sure on that.
However, C will essentially be in the middle. You will tell the C things about W, W will tell C things about you. C may let confidential things slip in your session or your Ws. Or C may not, but you will never know if she does or not. Also your C has to be impartial to both and your C may have already come to a conclusion about you and your situation which could be unfair to your wife.
My therapist told me that he is kinda in my corner on this. How can you trust your C to be in your corner if the C is also in your wife's corner and vice versa.
I think it's a bad position for you, your wife and the counselor. Or it could be some weird for of MC. Your W has issues she needs to work on, you have issues you need to work on. To be effective you should each have your own therapist.
Of course that's just my opinion.
Patience is bitter, but its fruit is sweet. --Jean Jacques Rousseau.
