Wyo. Stat. § 20-3-104
No other or greater evidence is required to prove the marriage of a husband and wife or that the defendant is the father or mother of a child or children than is required to prove such facts in a civil action. In a prosecution under this act no statute or rule of law prohibiting the disclosure of confidential communications between husband and wife shall apply. Both husband and wife are competent witnesses to testify against each other to any relevant matters including the fact of marriage and the parentage of the child or children but neither shall be compelled to give evidence incriminating himself or herself. Proof of the desertion of the wife, child or children in destitute or necessitous circumstances, or of the neglect or refusal to provide for the support and maintenance of the wife, child or children is prima facie evidence that the desertion, neglect or refusal is willful.
W.S. 20-3-104