Nebraska Revised Statute 43-1243
(a) Except as otherwise provided in section 43-1241, a court of this state may not exercise its jurisdiction under sections 43-1238 to 43-1247 if, at the time of the commencement of the proceeding, a proceeding concerning the custody of the child has been commenced in a court of another state having jurisdiction substantially in conformity with the Uniform Child Custody Jurisdiction and Enforcement Act, unless the proceeding has been terminated or is stayed by the court of the other state because a court of this state is a more convenient forum under section 43-1244.
(b) Except as otherwise provided in section 43-1241, a court of this state, before hearing a child custody proceeding, shall examine the court documents and other information supplied by the parties pursuant to section 43-1246. If the court determines that a child custody proceeding has been commenced in a court in another state having jurisdiction substantially in accordance with the act, the court of this state shall stay its proceeding and communicate with the court of the other state. If the court of the state having jurisdiction substantially in accordance with the act does not determine that the court of this state is a more appropriate forum, the court of this state shall dismiss the proceeding.
(c) In a proceeding to modify a child custody determination, a court of this state shall determine whether a proceeding to enforce the determination has been commenced in another state. If a proceeding to enforce a child custody determination has been commenced in another state, the court may:
(1) stay the proceeding for modification pending the entry of an order of a court of the other state enforcing, staying, denying, or dismissing the proceeding for enforcement;
(2) enjoin the parties from continuing with the proceeding for enforcement; or
(3) proceed with the modification under conditions it considers appropriate.
The statutory provision to contact the out-of-state court is not mandatory but merely directory. Garcia v. Rubio, 12 Neb. App. 228, 670 N.W.2d 475 (2003).