su trasero

his backside

→ su
phrase Rare #35,479
his backside Refers to a person’s buttocks or rear. It can also mean 'her backside' depending on context.
SP: Se sentó sin cuidado y golpeó su trasero contra la silla.
EN: He sat down carelessly and hit his backside on the chair.

Es lo que tiene ahora en su trasero.

That's what's in your ass now.

Desde hoy, traerán su trasero aquí al sonar el timbre y sin problemas.

From today onwards, they will bring their butts here when the bell rings, no problem.

— ¡Que te den profe! (2013)

Su trasero está expuesto al aire.

Her buttocks are exposed to the air.

— La vida es bella (1997)

No son sus ojos, ni sus manos, ni su trasero.

It's not her eyes, or her hands, or her butt.

— La doncella (2016)

Y un tipo mostrando su trasero.

And a guy showing his butt.

— Ne Zha (2019)

Miren su trabajo, no su trasero.

Look at their work, not their butt.

— El maquinista (2004)

Estoy tocando su trasero.

I'm touching her butt.