Answer
Negotiorum gestio is a quasi-contract that arises when a person voluntarily takes charge of the management of the abandoned or neglected business or property of another, without any authority or contract to do so (Civil Code Article 2144). The officious manager (the gestor) must exercise the diligence of a good father of a family and continue the management until the affair and its incidents are finished, or until the owner is in a position to take over (Articles 2144 and 2145).
The owner (dominus) who benefits from — or ratifies — the management is bound by the obligations the gestor contracted in his interest and must reimburse the gestor for necessary and useful expenses (Articles 2150 to 2152). No negotiorum gestio arises where the property is not in fact neglected or abandoned — for example, where it is being possessed or administered with the owner's tolerance.