I think that's why I like him! I translated his demeaner to be more, quietly aggressive, self confidence, assurance with just a hint of cockiness like he just KNOWS. Rollo, I think, feels envious, overshadowed and intimidated. He is anxious to prove he's as much a warrior/man as Ragnar and he feels slighted enough (that whole King thing at the Thing) to take action. Of course with that wench Siggy manipulating him and whispering subversive sweet nothings in his ear isn't helping.... It'll be very interesting to see Ragnar's reaction though I think he already has an idea...
Ragnar's sly grin is downright sexy. I also like how they began to establish One-Eye & that other dude as a bumbling duo in the finale... hope they continue that dynamic in S2.
Of course, I am also a big Game of Thrones fan. Our Blades are Sharp, House Bolton 2014!