Somehow, Geralt can sense John's words before they come. The noise he makes is quiet, acknowledging. He does not need John's gratitude but nor will he dismiss it. He has come to understand that it's important to John to speak these sentiments out loud.

"You are not," he answers firmly. "And believe me, John, you will more than earn your keep by entertaining the bard in my stead."

His tone is playful, but he's sincere. John isn't a burden and Geralt does not go out of his way for those who are not worth his while. John is more than a friend and more than a man he's shared a bed with. He's family. He's somebody Geralt spent several centuries with, who stayed with him through his loss of memories, who helped Jaskier find himself again at the end.

It's that last act that Geralt, deep down, sees himself repaying now. He knows John would not consider this the same, and for that reason, Geralt has not said it to John. But he does owe him for that.