None, although some believe that the Sugar Plum Fairy and her Cavalier, who dance the second act Pas de Deux, are supposed to be in love. The roles of Marie and the Nutcracker/ Prince are played by children, and in this version, they never dance formal ballet together. Marie wears a veil in the second act that looks like a bridal veil, but there is no indication that she and the Prince are getting married, or that they are even in love, just good friends.
A female belly dancer wears a costume with a bare midriff and performs the "Arabian Dance" which .is sometimes sensual but not in this version, so it's fine for children.