My sister and I were walking back from the bus and a woman came riding up on her bike beside us, talking about how crappy men are and how unlucky in love she is. We mumbled in agreement, etc, and thought we left her behind us. Then she rode up again and started talking about how men are wusses and pansies and girls when they don't do their "job" (whatever that is). I told her I didn't appreciate her comparing weak men to women, saying that it put women in a hierarchy under men. Well, I said it less academically. Eventually we ended up shouting and she called us lesbians, and then somehow I ended up yelling across the gas station area, "'Man up' is not an acceptable term!" At that point, I became the yelling lady and the circle was complete. The student became the teacher.
Honestly, I started talking back to her because I've had enough with people not living their beliefs. I believe in gender equality, even - especially - in language. How we speak and the words and idioms we use reveals our inner biases and beliefs. Inclusive language in church is another fine example of this exact thing. If we're for something, well then, let's be for it.
All in all, I just didn't want to think later, "Why didn't I say anything?" Casual sexism is sexism is sexism.
Would I have been nearly as vocal if it was a man, or a person of color of any gender? No. Her whiteness and gender made me bold in ways I wouldn't have if it was another person. Well, maybe it didn't make me bold, but it made HER non-threatening. I may have said something, but definitely not yelling the way I was.
Would I have even said anything if it was in a group of my friends or family?
Casual sexism is sexism is sexism.