Extend your love to all

Others may address you in a timely way or an untimely way.
They may address you with what is true or what is false.
They may address you in an affectionate way or a harsh way.
They may address you in a beneficial way or an unbeneficial way.
They may address you with a mind of good-will or with inner hate.

In any event, you should train yourselves:

'Our minds will be unaffected and we will say no evil words.
We will remain sympathetic to that person's welfare,
with a mind of good will, and with no inner hate.
We will keep pervading him with an awareness imbued with good will and,
beginning with him,
we will keep pervading the all-encompassing world with an awareness imbued with good will — abundant, expansive, immeasurable, free from hostility, free from ill will.'

That's how you should train yourselves.

Majjhima Nikaya 21, Kakacupama Sutta (The Simile of the Saw)