Husband's obsession for his grown up son

My husband retired a year ago.I am his second wife and have been married to him for 24 years. we have no children of our own but he has a daughter and a son from his previous marriage.His first wife is no more.I married him 3 years after her death.Now my step son is 29 years old.He is a lawyer by profession but not very stable in his career.My husband is smitten by his lad and keen to see him well settled but at the same time spoils him and makes him lazy.The son meanwhile is obsessed with his father's money and keeps making demands for some luxury item or the other...Now my concern is how secured is my position as his wife...my husband doesn't share anything with me but tells his son everything...he has invested 50k as life insurance for me for 5years and yet he bought a 15 lac SUV for his son with a snap of his finger..like a said he is retired and 61 years old..and to take a loan at his age with absolutely no monetary help from his son was in my opinion a foolish display of affection..I would like to know at this point as to what I should expect fro my husband to make my life secure so that I am not at the mercy of my step son if anything were to happen to my husband..Soon my step son will be married and his greed for his father's money will become twice as much..As you know Govt officers receive a lot of money after retirement ..My step son likes to live the life of a celebrity and his father and sister who is affluent make sure he gets everything he wants..Soon our limited income will be used in supporting his family as well because as of now he is 29 and living off us..Even my late father in law had willed the house in his name which is worrisome because he is very self obsessed and uncaring.son,,Please advice whether I should take the help of a lawyer because my relatives are of no help.