were talking
La mujer con quien estabas hablando es mi hermana.
The woman you were talking to is my sister.
Quiero saber con quién estabas hablando.
I want to know who you were talking to.
Si él no te gusta, ¿por qué le estabas hablando?
If you don’t like him, why were you talking to him?
La mujer, a la que le estabas hablando aquella vez, era mi hermana.
The woman you were talking to that time was my sister.
Por otro lado, ¿de qué estabas hablando?
On the other hand, what were you talking about?
— Toni Erdmann (2016)
El hombre con el que estabas hablando es mi tío.
The man you were talking to is my uncle.
Si no te gusta, ¿por qué estabas hablando con él?
If you don't like him, why were you talking to him?