Step-Mom knows it's been rough on you not being able to get out during these times to get you a girl. You confessed that you haven't even been masturbating. It's not good for a young man to hold in all that stress at your age. You need a release step-son. It's ok Step-Mommy is here to take care of you. She takes care of all your needs doesn't she? She cooks, cleans and gives you a place to stay well there's nothing wrong with her taking care of your sexual needs too.