I did not plan to respond to something with tufo to trolled, but I find it a good example of the few cases in Spanish where the separate prefix is used, since reality boy is a 'substantive - complement' form with two separate words and own meaning, so if ex- ( "which is no longer" ) he would join boy ( "young person") would end up saying that he is no longer a boy , and not that he no longer ceased to participate in a reality show ("television format") .
