No other or greater evidence shall be required to prove the marriage of the spouses, or that the defendant is the parent of the child or children, than is required to prove such facts in a civil action. In no prosecution under this chapter shall any statute or rule of law prohibiting the disclosure of confidential communications between spouses apply, and both spouses shall be competent and compellable witnesses to testify against each other to any and all relevant matters, including the fact of such marriage and the parentage of such child or children; provided that neither shall be compelled to give self-incriminating evidence. Proof of the desertion of the spouse, child, or children in destitute or necessitous circumstances, or of neglect or refusal to provide for the support and maintenance of the spouse, child, or children, shall be prima facie evidence that the desertion, neglect, or refusal is wilful.