It is illegal for children not to allow their parents to remarry.
Both parents' marriage and divorce belong to freedom of marriage, and no one can interfere. China's laws stipulate that children should respect their parents' marriage rights and should not interfere with their parents' divorce, remarriage and married life. Children's obligation to support their parents shall not terminate with the change of their parents' marital relationship.
[Legal Basis]
Article 1069 of the Civil Code states that children shall respect their parents' marriage rights and shall not interfere with their parents' divorce, remarriage and married life. Children's obligation to support their parents shall not terminate with the change of their parents' marital relationship.