How does Stilton treat Bertie at breakfast in Chapter 20? Why does he act this way?

At breakfast in Chapter 20, Stilton's behavior towards Bertie is completely different. Stilton treats Bertie cordially, and he explains to Bertie that he is grateful to be free of Florence and is now courting Daphne. He says that he now knows what love is, and that there is no hope for reconciliation with Florence.