If you don't want to say something, you can say "I'd rather not say" or "I prefer not to disclose that information." Alternatively, you can simply say "I don't want to say" or "I don't want to discuss that." It's important to respect others' boundaries and to feel comfortable communicating your own boundaries. If you feel uncomfortable or do not want to share certain information, it's okay to decpne to answer or to say that you prefer not to disclose that information.