Keep your focus on yourself and do not speak for your wife. Talk about your feelings, your actions, and let the C work on drawing out your wife. If she really is a good C, she has already figured out that your W likes to keep the focus on you, because that way she is not forced to change or introspect.
Take the high road, speak only about your own feelings, no tattling on what she said in confidence to you re: the C, and let her dig her own grave. She'll do it soon enough, don't you worry.
