Can I sue San Xiao for breaking the marriage after the divorce?

No, in the case that the third child is involved in the family, it cannot be solved through litigation. However, if a husband and mistress have a spouse, it is bigamy, or if they marry someone knowing that they have a spouse, it constitutes bigamy. The parties may report the case to the public security organ, which shall file a case for investigation and handling according to law. Whoever commits bigamy because he has a spouse, or marries another person knowing that he has a spouse, shall be sentenced to fixed-term imprisonment of not more than two years or criminal detention.