He has lived in Africa and in Southern Europe and thus, he speaks fluent German, English, Spanish, Italian and French.
He completed his acting training at the Etage in Berlin and at the Lee Strasberg Theatre and Film Institute in Los Angeles.
From 1999, he also took private acting lessons at the Summer Academy Theater with Herbert Fischer On 23 May 2003, he married the television host Charlotte Karlinder, three months after they had first met.
Together with actor Rhon Diels, he opened in 2006, the French Bar / Restaurant La Raclette in the Berlin district of Friedrichshain-Kreuzberg.
In 2008, Kusmagk took a guest role as eccentric fashion designer Niki di Lorenzo in Verbotene Liebe, where he shared most scenes with Miriam Lahnstein and Sina-Valeska Jung.
He stayed for the entire run of the season and won the reality show with a voting score of 69.77%; becoming "King of the Jungle".