Short answer. Generally yes, you may refuse. Rule 130, Section 25 provides that no person shall be compelled to testify against parents, other direct ascendants, children, or other direct descendants — except when such testimony is indispensable in a crime against that person, or in a crime by one parent against the other.
What the law says
No person shall be compelled to testify against his or her parents, other direct ascendants, children or other direct descendants, except when such testimony is indispensable in a crime against that person or by one parent against the other.
Rule 130, Section 25 — Parental and filial privilege. Read the full provision →
The general protection
Section 25 protects the family relationship from being forced into an adversarial courtroom role: no person shall be compelled to testify against parents, other direct ascendants, children, or other direct descendants. This is the parental and filial privilege — it lets a family member decline to be compelled to testify against another in this direct line. The protection runs specifically along the direct line of blood relationship — parents, grandparents, and other ascendants on one side, children, grandchildren, and other descendants on the other — rather than extending to collateral relatives such as siblings, aunts, uncles, or cousins, who fall outside the rule's wording.
Two narrow exceptions
The privilege is not absolute. It does not apply, and testimony can be compelled, when it is indispensable in a crime against that very person — for instance, where the witness is the victim of the ascendant's or descendant's crime — or in a crime committed by one parent against the other. Outside those two situations, the privilege remains available even where the testimony sought would otherwise be highly relevant to an unrelated case involving the family member.
Why the exceptions are drawn this narrowly
Both exceptions target situations where the family relationship itself is the source of harm being prosecuted, rather than an unrelated matter. Outside of being the crime's own victim, or a crime between the two parents, the privilege holds — preserving the family bond from compelled testimony in ordinary, unrelated proceedings. This keeps the privilege meaningful for its intended purpose — protecting the family relationship generally — while still allowing justice to be served where that very relationship is the source of the harm. The first exception applies only when the compelled family member is themselves the direct victim of the crime charged — not merely a witness to a crime against someone else in the family. The second reaches only crimes committed by one parent against the other, such as violence between spouses, not disputes between a parent and a more distant relative.