¡Qué poca madre!

¡Qué poca madre! is a vulgar expression that means What nerve! or How dare you/they! This is one of many obscene Mexican expressions involving madre, mother. For some reason, I associate ¡Qué poca madre! with chewing someone out for flirting — or worse — with your pareja.

• Por más buena que esté, eso no se hace. La verdad, ¡qué poca madre! No matter how hot your friend's girlfriend is, you don't have sex with her. That's fucked up. (movie dialogue)

The swindling old people out of their life savings would be another situation calling for ¡Qué poca madre!

¡Qué poca!

For mixed company the expression is often shortened to ¡Qué poca! For most learners, this is as far as you'll want to tread into profane territory. For effect, you can string along the silence as if you were going to say madre — the profane part — but without ever saying it: Qué poca ... Another way to soften the impact is to swap out madre for abuela: Qué poca abuela. Apparently grandmothers can be invoked with less volatility.

No tienes madre

Another alternative is No tienes madre: You have no shame.

Descaro

Descaro means nerve, so ¡Qué descaro! means: Such nerve! You ought to be ashamed of yourself!

• ¿Con qué descaro le hablas a mi hija? Exactly who do you think you are, talking to my daughter? How dare you talk to her! (telenovela dialogue)

The adjective is descarado, shameless. De plano se me hace muy descarada esa actitud.