sus dos

both of their

→ su
phrase Uncommon #19,058
both of their Used before a plural noun referring to a pair of things or people: sus dos hermanos = both of his/her brothers.
SP: Sus dos hijos viven en Madrid.
EN: Both of his children live in Madrid.

Sus dos últimas películas fueron un desastre.

His last two films were a disaster.

— State and Main (2000)

Nos miró como si le hubiéramos pedido sus dos riñones.

He looked at us as if we had asked him for both of his kidneys.

— 3 Idiots (2009)

De lo contrario, Britt perderá a sus dos padres hoy.

Otherwise, Britt will lose both of her parents today.

— Sin piedad (2026)

También sus dos amigos, Sócrates y Platón.

Also his two friends, Socrates and Plato.

— Las invasiones bárbaras (2003)

De sus dos sugerencias, creo que prefiero la primera.

Of your two suggestions, I think I prefer the first one.

Él no conoce a ninguno de sus dos hermanos.

He doesn't know either of his two brothers.

Se sentó entre sus dos mejores amigos en la fila del cine.

He sat between his two best friends in the movie theater row.

Sus dos hermanos son profesores.

His two brothers are teachers.

No he leído ninguna de sus dos novelas.

I haven't read either of his two novels.

La abuelita viajaba con sus dos nietos.

The grandmother was traveling with her two grandchildren.

Coja sus dos mejores camiones.

Take your two best trucks.

— El salario del miedo (1953)

Sus dos padres murieron.

Both of his parents died.

Sus dos abuelos están muertos.

Both of his grandparents are dead.

Chico y Ramón, sus dos hermanos, también eran mis amigos.

Chico and Ramón, his two brothers, were also my friends.

— El bueno, el feo y el malo (1966)

El huérfano se reunió con sus dos hermanas cuando tenía cinco años.

The orphan was reunited with his two sisters when he was five years old.