In Castillo vs. Castillo, the trial court improperly applied the unclean hands doctrine to summarily deny a petition for modification. Where a spouse has the ability to pay an arrearage and does not do so, he is not in court with clean hands and in such case his petition should not be considered on the merits until he has complied with the former order by payment of the sums due thereunder. But there must first be an evidentiary hearing to determine whether the spouse had the present financial ability to comply with the prior order, which was not done in this case.