his doing
Señor Shukla, ¿ha sido cosa suya?
Mr. Shukla, was this your doing?
— Dil se.. (1998)
Eso es cosa suya.
That's up to you.
— La linterna roja (1991)
Tom decidió que no era cosa suya decirle a Mary lo que John había hecho.
Tom decided it wasn’t his place to tell Mary what John had done.
Es cosa suya.
It's up to you.
Ha sido cosa suya.
It was his doing.
— Malèna (2000)