I married my wife when the firt born daughter was 7 years and sweet. We have our own daughter who is reaching 5 years. Our step daughter is now 15 years and she is treating me so badly. I cannot do or say anything to her and her attitude has affected my relationship with my wife. I am almost packing up and leaving as the both seems to gang up on me. I feel like i will one day beat her up so bad and i know that will be social services or maybe jail. She says I am not her dad, come home after midnight and hangs out so oftenly. She demands money from us and she has very expensive fashion needs i cannot keep up with. He mum does not know what to do either but she sometimes agrees with the daughter. Its such a mess and i am so much regretting our relationship. How long can this go for because i will go mental. Please help.