tell it to him, tell it to her, tell it to them, tell it to you (formal)
Llama a Montes y cuéntaselo.
Call Montes and tell him about it.
— El guardián invisible (2017)
Vale, pero cuéntaselo.
Okay, but tell them about it.
— 7 años (2016)
Cuéntaselo todo, hazlo.
Tell them everything. Go ahead.
— Hogar (2020)
Cuéntaselo, no pasa nada.
Tell him about it; it’s okay.
Cuéntaselo, que se va a alegrar.
Tell him, he’ll be happy.
— Jaula (2022)