David affirmed that he was dancing before the Lord and thus not in order to find a new lover. When he then contrasts himself with Saul, that is meant to emphasize his humility. He was humbled by the fact that God had made him king over Israel and he would rejoice in this reality while remaining a loyal servant of the Lord.
21 David répondit à Mical: C'est devant l'Eternel, qui m'a choisi de préférence à ton père et à toute sa maison pour m'établir chef sur le peuple de l'Eternel, sur Israël, c'est devant l'Eternel que j'ai dansé.