Just out of curiosity, did Stannis say that shyt about not making the same mistake as Ned in the books?
If not, I'm inclined to think HBO switched that up. Which would be a good thing, imo. Book Stannis sounding like a hoe right now. How can he be all about that honor and shyt if he failed to do his duty in informing his brother (especially after he thinks Cersei killed Jon Arryn). Wether Robert believes him or not, you gotta tell him, man.
The mistake u talking about is ned only telling him right? Yea he does say that right before he sends the letter to every castle in westeros..
The thing u gotta understand about Robert and stannis...them nikkas did NOT get along at all. It was just a straight up hateful relationship, that's why you hear Robert tell Ned "I never loved my brothers..you were the brother I chose".
Robert did a lot of dirty shyt to stannis like giving storms end to renly after stannis not only defended it in a long hard siege, but he was next in line to inherent it and robert skipped him. In fact after the siege, Robert thanked Ned for lifting the siege and not Stannis for defending it. Then he sends Stannis to capture dragonstone with his ships which stannis does but all Robert does is blame him for dany and vyseris escaping
Robert also fukked a bytch in stannis wedding bed before stannis even got a chance to with selyse on their wedding night so he took that as a jab at the honor of his wife's family which also pissed him off
And the final nail in the coffin was Robert making Ned hand of the king. Stannis n Jon arryn were both running shyt for years on the small council and stannis was getting closer to the truth about Jamie and cersei and Robert once again didn't even think about him. So he bounced to dragonstone to "regroup and think of his next move"...I think that's when he met melisandre