A photo of a newborn baby beaming up at her dad has captured people's hearts and gone viral on social media. New father, Flávio Diego Vilela Dantas, posted a picture of his bundle of joy smiling at him on Instagram.

Fathers and daughters seem to have a special bond. This story of Flávio Dantas, of Rio de Janeiro, Brazil, gives us another proof of it.

The new dad was so excited to meet his daughter, Antonella, that he spoke to her all the time. Even when she was still in her mother's belly.

Tarsila Rosa Cordeiro Batista, Dantas' partner, explained that every morning before she would go to work, Flávio would greet her baby, and stroke her belly, saying: "I'll always be there." And whenever he did this, the baby would kick and move.

She said:

"He always told her that he loved her so much. Good morning when I went to work, arrived good afternoon, said I'd always be there, kept stroking my belly… And amazingly, it always seems at the same time every day she started to move."

After Antonella was born, the hospital staff laid the sleeping baby on her mother's chest. What happened next warmed her parents' hearts.

The father began talking to his newly born daughter as usual. She suddenly opened her eyes and smiled up at him.

In an interview with a Brazilian news site, Batista said:

"They put her on top of me sleeping, and as soon as he spoke to her, Antonella opened her eyes and smiled!"

A nurse caught the heart-melting moment on camera, and Dantas described his feelings about it in an Instagram post:

"I can't explain the feeling I felt at that moment. Every day I would talk to my daughter in her mother's belly, I would always tell her that I loved her, that Daddy was there, and that I was going to be the best father in the world! When she was born, look, how did she repay me? With that delicious smile."

This lifetime experience overwhelmed Dantas, and he couldn't describe his love for his newborn daughter. He said that this love was "too big to fit inside his chest."

Since babies can process sounds as soon as they're 16 weeks old after conception, Antonella had time to get used to her dad's voice.

And after 26 weeks through the pregnancy, unborn babies noticeably react to noises from the outside.