to them
She introduced herself to them.
I can't lie to them.
I bought snacks for them.
We have a surprise for them.
As pessoas são gentis quando se é útil para elas.
People are kind when you're useful to them.
— O Carteiro e o Poeta (1994)
Não gosto quando as pessoas me pedem para fazer coisas para elas.
I don't like it when people ask me to do things for them.