My husband and I came to visit his son in CA. My stepson decides that he does not want his dad to talk to me anymore. What can I do?

Sorry, I don't understand the question. You and your husband went to CA to visit his son - is this son also your stepson, or is the stepson someone else entirely? If you and your husband are married then it's pretty impossible for you not to speak to your own husband, right? Sorry, maybe try to rephrase the question?