No. A notarized agreement that says “we will not interfere with each other’s relationships” is legally void as to its effect on the marriage. Under the Family Code, marriage is a permanent union. No private contract between spouses can authorize either party to commit adultery or concubinage.

However, such an agreement may have an important practical effect: it can serve as evidence of consent. Both adultery and concubinage require proof that the act was committed without the other spouse’s consent. A signed document agreeing that your spouse may engage in other relationships can make a criminal prosecution difficult because the consent negates an essential element of the offense.

Adultery (Article 333, Revised Penal Code) — Committed by a married woman who has sexual intercourse with a man not her husband, and by the man who has intercourse with her knowing she is married. A single act is sufficient for conviction.

Concubinage (Article 334, RPC) — Committed by a married man who keeps a mistress in the conjugal dwelling, cohabits with her elsewhere, or has intercourse under scandalous circumstances. Requires more than a single act — it demands proof of an ongoing relationship or cohabitation.

The agreement is not a license to commit adultery or concubinage. But if a prosecution is filed, the defense will argue that the complaining spouse consented, therefore no crime was committed. The court will examine whether the consent was genuine, freely given, and whether it was subsequently revoked. A spouse who later changes their mind and files a criminal complaint may still succeed if they can show the consent was withdrawn before the alleged acts occurred.

This principle comes from the nature of these crimes: they are private offenses that require the offended spouse’s initiative to prosecute. If the offended spouse consented to the acts beforehand, the prosecution cannot claim the act was committed against their will.

If you and your spouse are separated and wish to formalize your arrangement, consider these options instead of a “non-interference” agreement:

• Legal separation — A court process that addresses support, custody, and property without dissolving the marriage bond. Infidelity is a ground for legal separation.
• Annulment or declaration of nullity — The only way to be free to remarry under Philippine law. Requires proving a ground under the Family Code.
• Separation de facto agreement — A private document covering support, custody, and property division during separation. This does not allow remarriage but can clarify financial arrangements.