Now, all of the internet is crying.
The San Antonio boy can be seen strumming on a toy guitar and baby-singing lyrics in tune with the slower, lullaby version of "Remember Me."
The Deais told mySA.com that their baby girl was born with hydronephrosis, a kidney condition. She passed away last May at only four months old.
My son singing "Remember Me" from the movie "Coco" to his baby sister, Ava, who we lost this past May.— Samir (@SAM1R) December 31, 2017
He's only 4 years old and he understands. He didn't even know he was being recorded. He just wanted to sing to her for her 1st birthday!
Happy Birthday mamas, we miss you!💕 pic.twitter.com/EoVLjju0bJ
Samir said Coco helped his son cope with the loss and understand the Dia de los Muertos tradition. He said he's thankful for the movie's presence in their healing and that the family was moved by the positivity coming from the video going viral.
The Deais family is expecting to welcome a third child, who will be named Stella Grace.
My wife and were literally brought to tears seeing how much love Alex and Ava and our family has received. We were FLOORED last night!! I couldn't me more thankful. Thank you to everyone from our little family! What a 1st birthday baby girl! 🌻💕— Samir (@SAM1R) January 2, 2018
All Glory to God #StayHumble