R. Star wrote:
It probably came from when he learned Sisko punched Q. Even deep down Worf didn't have the brass to hit Q as much as he disliked him.
There is also the scene in Rules of Engagement
where Sisko gives Work a world-class ass-chewing. Epic stuff.
Before that, there was also the scene in Sisko's office during Sons of Mogh
. The scene starts off with Sisko glaring at Worf across his desk, with the latter staring at his boots. Clearly, Sisko made Worf uncomfortable.