sin su permiso

without their permission

→ sin
phrase Rare #48,235
without their permission The possessive su can mean his, her, or their depending on context.
SP: No puedes usar mi computadora sin su permiso.
EN: You can't use my computer without their permission.

No deberías leer las cartas privadas de la gente sin su permiso.

You shouldn’t read people’s private letters without their permission.

Nos casamos sin su permiso.

We got married without their permission.

— Bajrangi Bhaijaan (2015)

A decir verdad, conduje el carro de mi padre sin su permiso.

To tell the truth, I drove my father's car without his permission.

El bastardo me dijo que nadie podía morir sin su permiso.

The bastard told me that no one could die without his permission.

— La diva (1981)