An anonymous note from a stranger brightened a difficult Father's Day for a bereaved family.

As parents Dan and Maxi Cortez, and their daughters Harper and Harlow were finishing their meal at a restaurant, a waitress handed them a heartwarming note.

A kind stranger that was sitting nearby had paid for their meal, and scribbled a message on the back of the receipt:

"Happy Father's Day!" The note read. "Enjoy your babies, they don't stay little long. From the family across from you. God bless you."

Dan Cortez with triplets Landon, Harper and Harlow. Photo / Facebook/Maxi Cortez
Dan Cortez with triplets Landon, Harper and Harlow. Photo / Facebook/Maxi Cortez

Moved by the kind gesture, Maxi shared the message on Facebook. In the post, she thanked the anonymous note-writer, and explained why it meant more to them than the stranger could ever realise.

"To the family that sat across from us at Red Lobster today," she wrote on Facebook. "You never ask a question we never spoke a word. Yet you did something for us that we will never forget. When the waitress handed us your note the tears began to fall.

"To you we looked like just a family of four celebrating the most important man in our lives. Little did you know last year we celebrated as a family of five."

The note explained how the family lost one of their triplets last year, and that holidays were a difficult time for them.

"You might never know our story or the impact of something so little could effect our lives," Maxi wrote on Facebook. "I'm writing you to thank you from the bottom of our hearts!"

After a long struggle with infertility, Dan and Maxi underwent IVF and had healthy triplets, Landon, Harper and Harlow.

Tragically, Landon passed away a few weeks later from meningitis.

Posted by Maxi Cortez on Saturday, 16 July 2016

The meal at the restaurant marked the family's first Father's Day without their son.

Writing on Facebook, Maxi said she hoped the kind stranger at the restaurant would see her message.

"I hope this post reaches you, so one day you might know that what may have seemed like a small gesture of kindness to you, made celebrating my wonderful husband just a little bit easier this year!"