Get to know Norway's Crown Princess Mette-Marit's oldest son Marius Borg Hoiby

While Crown Princess Mette-Marit of Norway is busy with royal duties, her 19-year-old son, meanwhile is turning heads and making girls swoon around the world. The teenager, who is an avid user of social media, is just like any other teen, taking selfies, enjoying time with friends and spending time on the beach. Here are some fast facts about Norway's royal son Marius Borg Hoiby.

He is into social media.

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Photo: Tumblr/mariusborghoib

Marius has an active Instagram account, with over 18,000 followers, and Tumblr page just like any other teen. The teen updates his Tumblr page quite frequently with selfies, beach pics and of course, pics of his squad.

He is into extreme sports.

Photo: Tumblr/mariusborghoib

Swimming, surfing and skateboarding are some of the teen's hobbies. He spent some time catching waves during a family vacation in Portugal and has the photographs to prove it. He also enjoys soccer. Marius was seen enjoying the Norway vs. Hungary playoff game with his family last November.

He's not a prince.

Photo: Getty Images

Marius is son to Crown Princess Mette-Marit from her previous relationship with advertising executive Morten Borg. His two half-siblings, sister Ingrid Alexandra, 11, and brother Sverre Magnus, 9, whose dad is Prince Haakon, are the next heirs to the Norwegian throne, but he still gets plenty of royal treatment and has been unofficially adopted by the Norwegian court.