Can husband give all his property to his extra marital affair

Sir, My husband is having an extra marital affair with our maid for the past few years and now he is willing to give all his property to this maid. He has already given 30 sovereign of gold and few lakhs in cash, but i could nothing as he was very threatening. Now he is planing to sell the land and house which we are currently living in (property is solely registered in his name) and give the money to his extra marital affair.. He is also threatening me and my son to leave his house.. Me and my son are his legal wife and son.. I have been living with him for the past 34 years and still but now suddenly he is planning to give all his wealth to his extra marital affair without giving a single penny to me and my son..My son is going through depression due all this family issues.. So Does me and my son have legal right in his property? Can he will his property to his extra marital affair? What are the legal precautions that me and my son could take? I kindly request you to advice me on this matter. NB: MY AGE 57. HUSBANDS AGE 64, HIS LEGAL SONS AGE 30... Also as far as i know he dont have any illegal kids... I