Before you watch this video, I have to warn you to mentally prepare yourself.
If you've seen Pixar's Coco, you'll understand how sweet and heartbreaking this moment truly is.
The video, captured by dad Samir Deais, shows a little boy named Alex serenading the altar of his sister, Ava Lynn, who passed away in May.
Watch the sweet clip below:
Alex was singing to the altar on what would have been Ava's first birthday, and as his dad wrote, he had no idea he was being recorded at all.
Rather, he just wanted to sing to her for her birthday, and what a beautifully perfect song to sing.
Samir shared a follow up message on Twitter regarding the response to the video: