I knew it wouldn't be so simple, and damn that Sima Yi at the end. Author really know how to make grand entrance.
Also Sun Quan reminiscing his two brothers hit me in the feeling
@Liar now that you mentioned it, i always forget that Sun Quan in this series regard Sima Yi wife as both his teacher and sister, and there is dialogue when Sima Yi talking to his wife that not many hit it off with him as much as Sun Quan.
So yeah i guess Sima Yi and Sun Quan regard each other as brothers