Analyze your own attitudes toward your step mother. Ask yourself if you are contributing to the conflict by making snide remarks, not including her in family events, or being rude yourself. It's common for step children to feel resentment or hostility toward their step mother out of loyalty for their own mother or possessiveness toward the other parent, explains Martin.

Try to understand why your step mother is rude. According to Catherine Rondina, author of the book "Rudeness: Deal With It if You Please," there are many underlying factors that can drive a person to be rude, and understanding them will make it easier for you to deal with her behavior. Perhaps she is acting that way because she feels threatened or doesn't feel included in the family. Ask her if there is something bothering her or why she is treating you that way.

Confront your step mother about her behavior. Ask to have a private conversation where you can sort out your differences. Explain how her behavior makes you feel by using "I" statements. Avoid phrases beginning with "you" that can lead her to feel blamed or attacked and will only put her in defensive mode.

Make a decision to ignore her behavior and not let it get to you. If she does not change after you tried to fix your relationship, ignoring the behavior might be your best option. Keep in mind that maintaining a positive relationship with your father is worth putting up with the rudeness, so long as it doesn't get too out of hand.