When Haakon and MM married, Marius was just 3 yr, old and his father Martin was already in prison, I don't know if Marius had much contact with his natural father while Martin was in prison, if he was allowed to see his father for visits, nothing was ever written.
Martin was released from prison when Marius was either a tween or early teens. Martin went on to marry his girlfriend and he straightened up and to my knowledge leads a clean life without any other run ins with the law. There are some photos of Martin and his family with Marius plus Haakon and MM, the two couples would have get together fairly regularly. I don't know how much Marius and Martin remained in contact when he became a young adult, nothing has been reported.
I read in a royal gossip column several years ago that Marius always resented not getting some kind of royal title and he resented his siblings from both his mother and father's marriages. I took it with a grain of salt until I viewed some photos of Marius looking at Ingrid Alexandra and Sverre Magnus and the look of resentment was so obvious, it was scary.