If a married man donates property such as a condominium unit, land, jewelry, or even a motor vehicle to his paramour, is such a disposition valid under Philippine law? Many people assume that as long as the property belongs exclusively to the husband, he may freely do with it as he pleases. 

However, the law takes a different view when the donation arises from an illicit relationship. In such cases, the transaction does not merely raise an ethical question; it crosses the boundary of legal validity.

Article 739 of the Civil Code provides a clear directive. The following donations shall be void:

1. Those made between persons who were guilty of adultery or concubinage at the time of the donation;

2. Those made between persons found guilty of the same criminal offense, in consideration thereof; and

3. Those made to a public officer or his relatives by reason of his office.

The first category is the one most frequently encountered in actual controversies. If a man maintains a relationship falling within the definition of concubinage, any donation to his mistress is void. Likewise, if the woman is married and engages in sexual relations with another man, she commits adultery, rendering any donation between them invalid. These offenses are defined under Articles 333 and 334 of the Revised Penal Code.

The law goes further. It authorizes the legal spouse — whether of the donor or the donee — to file an action to annul the donation. Crucially, the law does not require a prior criminal conviction to establish adultery or concubinage. The Civil Code itself states that the guilt of the parties may be proven in the civil action for nullity by a mere preponderance of evidence. The standard in criminal cases — proof beyond a reasonable doubt — does not apply. Proof may rest on circumstances, acts, communications  and other evidence that demonstrate the illicit relationship.

The Supreme Court in Insular Life Assurance Co. Ltd. v. Ebrado (G.R. No. L-44059, 28 October 1977) provides a compelling explanation of the policy rationale underlying Article 739. In that case, the Court held that common-law spouses are barred from receiving donations from each other because the law seeks to protect the rights of the legitimate family. The Court noted that the same principles apply to life insurance policies, where a beneficiary is legally akin to a donee. 

The prohibition is not limited to donations per se. A mistress is likewise barred from:

· Being named as a beneficiary in the life insurance; policy of a married man (Article 2012, Civil Code); and

· Being instituted as an heir in his will (Article 1028, Civil Code).

The same applies in reverse, meaning a married spouse cannot legally receive a donation, inheritance, or insurance benefit from his or her paramour. These prohibitions reflect a consistent legal doctrine: the law does not recognize or reward arrangements arising from an illicit relationship.

It bears repeating that no criminal action for adultery or concubinage needs to be pending or proven. The civil case itself may determine the existence of the illicit relationship, and if the evidence tilts in favor of such finding, the donation is void. The standard is a preponderance of evidence, not proof beyond reasonable doubt.

In sum, when donations are made in the context of an unlawful relationship, the law treats them as invalid, not merely questionable or suspect. It is not only a matter of legal formality but a matter of public policy. The law draws a line and once crossed, the donation cannot stand.