Mark 10:8-12

and the two shall become one flesh; so they are no longer two, but one flesh.

Therefore, what God has joined together, no person is to separate.”

And in the house the disciples again began questioning Him about this.

And He *said to them, “Whoever divorces his wife and marries another woman commits adultery against her;

and if she herself divorces her husband and marries another man, she is committing adultery.” Jesus Blesses Little Children