Growing up, he played youth football alongside current Paris Saint-Germain defender Layvin Kurzawa when the pair lived in Fréjus.

[3] In December 2019, he was arrested in Belo Horizonte, Brazil, accused of sexual harassment for slapping a woman's behind without her permission.

N'gapeth in the next year moved to Kuzbass Kemerovo, a club playing in Super League; however, during the season he abandoned the team and returned to Italy, wearing the shirt of Modena in the Serie A1.

[7][8] On October 7, 2010, N'Gapeth was expelled from the national team on disciplinary grounds during the World Championship held in Italy.

On October 18, 2015, the French national team, including N'Gapeth, won the title of the European Champion 2015 (3–0 with Slovenia in the finale).