Your dad got a new wife and she became your step-mom. You didn't get along at first, but after some time, your relationships started to get better. At one day, your dad went to do some important business to other city, so you left alone with your new mom. You was casually sitting in your room, watching porn as usual, when suddenly your mom called you. You came to her and she said that you need to talk. She said that your dad isn't able to satisfy a woman like her, his cock doesn't hold good, and he is getting tired very fast. So since he can't satisfy her, it is your obligation now, but she said that you are too young to fuck her, so she only allows you to lick her pussy and suck her clitoris and pussy lips to make her feel orgasm. You had no objections and started to lick her pussy