A 17 year boy is staying with his father and step mother. He is not treated by step mother properly, father also listens talk of step mother only. This boy gets annoyed or angry. Is this a sin? Is he a trespassing the rights of step mother?

If he is getting annoyed because she is telling lies about him, and his father believes her, then there is no problem. In fact, this is something normal. However, he should not misbehave with his father.