Wash. Rev. Code § 26.09.530
In determining whether to permit or restrain the relocation of the child, the court may not admit evidence on the issue of whether the person seeking to relocate the child will forego his or her own relocation if the child's relocation is not permitted or whether the person opposing relocation will also relocate if the child's relocation is permitted. The court may admit and consider such evidence after it makes the decision to allow or restrain relocation of the child and other parenting, custody, or visitation issues remain before the court, such as what, if any, modifications to the parenting plan are appropriate and who the child will reside with the majority of the time if the court has denied relocation of the child and the person is relocating without the child.
RCW 26.09.530
Intent-Captions not law-2000 c 21: See notes following RCW 26.09.405.