Remind yourself that it is your step-dad’s problem and your mother’s problem, but it is not yours. Do what you can to save up enough that you can go back to your own place. Your mom is a grown up and so are you, so you both need to take care of yourselves and not worry too much about other adults. 1) So what if he isn’t pulling his weight? You do the best you can and then get out of there as soon as you can. Don’t be jealous that “somebody seems to like him best.” Actually, you should feel sorry for him in that he was never taught life skills (but not sorry enough to ever lend him money). 2) Why do you care if no one ever marries him? Just don’t marry him yourself. 3) Your mom is an adult and she chose to marry this guy and let his son live with her. There is nothing you can do except offer a shoulder to cry on or an ear to listen if she needs it. So what if she ends up divorcing your step-dad? There are no little children involved who can be hurt, so let your mom deal.