Is Article 87(8) of Regulation (EC) No 883/2004 of the European Parliament and of the Council of 29 April 2004 on the coordination of social security systems to be interpreted as meaning that a person who, before 1 May 2010, began to pursue an activity as an employed person in the Grand Duchy of Luxembourg and an activity as a self-employed person in Belgium must, in order to be subject to the legislation applicable pursuant to Regulation 883/2004, submit an explicit request to that effect, even if he was subject to no obligation to pay contributions in Belgium before 1 May 2010 and was made subject to the Belgian legislation on the social security scheme for self-employed persons only retroactively, following the expiry of the three-month period starting on 1 May 2010?

If the first question is answered in the affirmative: does the request referred to in Article 87(8) of Regulation 883/2004 and submitted in the circumstances described above entail the application of the legislation of the competent State pursuant to Regulation 883/2004 with retroactive effect from 1 May 2010?