As we all know, Someshwar is already dead. Thus, Prithvi is sort of the head of the house now. There is no one telling him what is wrong and what is right (at least not an older person who actually has the right to do so).....
There is no one present to tell him what to do........
I think that if Someshwar was still alive, then he would've NEVER let Prithvi leave the Kingdom and run after Sanyo.....Someshwar would've given Prithvi one of his "Ek raja......." speeches.......
I think this would've helped Prithvi do the right thing..........but since Someshwar is dead and Prithvi is still a teenager, he will have to go through some things in life that he wouldn't have gone through if Someshwar was alive....