Adultery: Common Law more unbiblical than Canon Law?

Under common law, a married man can only be guilty of adultery if he fornicated with a married woman not his wife.  Under English canon law, adultery can be committed by either married spouse.  So oddly enough during some point in English history, common law kept the Biblical definition of adultery and canon law broadened the definition.

Fornication in England was punished in the ecclesiastical courts and was only dealt with by common law if it was committed in the open, notoriously, or became a public nuisance.  The United States did not inherit the ecclesiastical courts.  However the United States inherited much of their common law from England and likewise did not punish fornication done in private, except when punishable by a statute.  Most states have enacted statutes. Some states used the common law definitions while some used the canon law definitions.  Some states left the crime undefined leaving the courts to decide between canon and common law.[1]