"Narada, Don't try to put words in the mouth of Durvasa, We were talking about it, It's not your place to say anything about how we conduct the business here, Go away."
Shukracharya is quick on to the trick of Narada, as the user of tricks and Maya himself, he knows very well when someone uses the same tricks against him, and right now Narada is doing so.
He finds out that there is a conflict about who will be the Guru of Karna, which creates tension between him and Durvasa, And now Narada is ready to use that fact against them.
Shukracharya knows that this is quite an effective trick, especially against someone like Durvasa, Who though smart and wise but tends to let anger overcome him and lead the way.
