I think there is a divorce case in which your husband wants to use those messages. First of all, you had not sent those messages. Hence, the court shall not take it into account because it is not an admission from the party to suit.
Those messages are however relevant evidence but they are not admissible under the Indian Evidence Act. Your minor son would not admit in the court that those messages are true. Because he has no evidence to prove that they were true. It might be a tactic of your husband to create some evidence against you through inducing the son.
Whenever your husband produces that evidence before the court, you should oppose it. The court shall not admit that evidence because it was not your admission. No need to worry.