While it’s known that Leopold disapproved, what is not known is the discussion between father and son as Leopold’s letters were said to be destroyed by Constanze.
Mozart quickly found work in Vienna, taking on pupils, writing music for publication, and playing in several concerts. He also began writing an opera Die Entführung aus dem Serail (The Abduction from the Seraglio). In the summer of 1781, it was rumored that Mozart was contemplating marriage to Fridolin Weber’s daughter, Constanze. Knowing his father would disapprove of the marriage and the interruption in his career, young Mozart quickly wrote his father denying any idea of marriage. But by December, he was asking for his father’s blessings. While it’s known that Leopold disapproved, what is not known is the discussion between father and son as Leopold’s letters were said to be destroyed by Constanze. However, later correspondence from Mozart indicated that he and his father disagreed considerably on this matter. He was in love with Constanze and the marriage was being strongly encouraged by her mother, so in some sense, he felt committed. The couple was finally married on August 4, 1782. In the meantime, Leopold did finally consent to the marriage. Constanze and Mozart had six children, though only two survived infancy, Karl Thomas and Franz Xaver.