There is no Biblical grounds for divorce, except for violation of the espousal period in the Jewish model under the Law. The "exception clause" does not apply to a Gentile marriage. Jesus did not say it was allowed, He specifically forbade it in Matthew, Mark, and Luke.
Separation from sin and abuse, yes; divorce, no.
Separation from sin and abuse, yes; divorce, no. Good summary. And then the disciples said, "In that case, it is not expedient to marry." The demand for divorce and remarriage is no new thing.