Modification of custody or decision-making responsibility

(1) If a motion for modification of a custody decree or a decree allocating decision-making responsibility has been filed, whether or not it was granted, no subsequent motion may be filed within two years after disposition of the prior motion unless the court decides, on the basis of affidavits, that there is reason to believe that a continuation of the prior decree of custody or order allocating decision-making responsibility may endanger the child's physical health or significantly impair the child's emotional development. (2) The court shall not modify a custody decree or a decree allocating decision-making responsibility unless it finds, upon the basis of facts that have arisen since the prior decree or that were unknown to the court at the time of the prior decree, that a change has occurred in the circumstances of the child or the child's custodian or party to whom decision-making responsibility was allocated and that the modification is necessary to serve the best interests of the child. The trial court retains jurisdiction to modify an order allocating decision-making responsibility pursuant to this section during the pendency of an appeal. In applying these standards, the court shall retain the allocation of decision-making responsibility established by the prior decree unless: (a) The parties agree to the modification; (b) The child has been integrated into the family of the petitioner with the consent of the other party and such situation warrants a modification of the allocation of decision-making responsibilities; (b.5) There has been a modification in the parenting time order pursuant to section 14-10-129, that warrants a modification of the allocation of decision-making responsibilities; (b.7) A party has consistently consented to the other party making individual decisions for the child which decisions the party was to make individually or the parties were to make mutually; or (c) The retention of the allocation of decision-making responsibility would endanger the child's physical health or significantly impairs the child's emotional development and the harm likely to be caused by a change of environment is outweighed by the advantage of a change to the child.