When Xu Shu and Cheng Yu were in Yingchuan, they had met before, but at that time, it was Cheng Yu chasing Xu Shu in a fight. Now neither of them relies on martial force anymore and instead uses their brains, so when they see each other, there's a bit of "nostalgia for the heroic days," which, of course, is nonsense.
It's probably more about watching others fight to death while they enjoy the spectacle from behind, especially for strategists like Xu Shu and Cheng Yu who already have a sage's instinct.
During the conversation between Liu Bei and Cao Cao, Chen Xi didn't deliberately eavesdrop and honestly wasn't keen to get involved. Chen Xi believed that the two could resolve their issues by themselves. However, just when Chen Xi hadn't even excitedly started chatting, Liu Bei called him over.
