It was in his capacity as literary adviser that he incurred the wrath of the King's eldest son, Prince Jesdabodindra, also a poet. Sunthorn Phu ventured to make public criticism of some lines written by the Prince, sometimes going to the extent of improving the lines by rewriting them extempore, a kind of work at which he was particularly adept. The Prince took this as a personal slight, and unfortunately for the poet, never forgot it and never forgave him for it.