Are the competent social security authorities of one Member State (in this case the Caisse pour l’avenir des enfants (Children’s Future Fund), Luxembourg) required, pursuant to their Community obligations under Article 45 TFEU, Directive 2004/38/EC of the European Parliament and of the Council of 29 April 2004 on the right of citizens of the Union and their family members to move and reside freely within the territory of the Member States and Regulation (EC) No 883/2004 of the European Parliament and of the Council of 29 April 2004 on the coordination of social security systems, in particular Article 4 thereof, to pay family benefits to a national of a second Member State when, under identical conditions for the grant of those benefits, those competent authorities recognise the entitlement of their own nationals and residents to family benefits, pursuant to a bilateral international convention concluded between the first Member State (Luxembourg) and the third country (Brazil)?

In the affirmative, and in the event that the approach taken in the judgment in Gottardo is extended to the context of family benefits, can the competent social security authority, more particularly the competent authority for family benefits – in this case, the Caisse pour l’avenir des enfants (Children’s Future Fund), the national agency of the Grand-Duchy of Luxembourg for family benefits – rely on objective grounds based on considerations relating to the extremely heavy financial and administrative burdens faced by the authority in question to justify a difference in treatment between nationals of countries that are contracting parties (to the bilateral convention concerned) and other nationals of European Union Member States?