This teen duet of 'Shallow' from 'A Star Is Born' is giving us chills

The two teens have blown away millions after their video went viral on Facebook.

Christopher Halligan, 19, and Jessica Reinl, 17, sang the rendition alongside the Mount Sion Choir in Ireland. It was originally performed by Lady Gaga and Bradley Cooper in the movie.

Choir director Colette Kearney told "Good Morning America" that Halligan and Reinl only rehearsed the song one time and that they are "astounded by the response" they've received from around the world.

"When they sang it that night, it came as a beautiful surprise to everyone... as I looked around the room so many people were crying tears of happiness," Kearney said. "We asked them to stay back and we recorded the clip that most people have seen."

She added, "The respect and awe that Christopher has for Jessica is completely genuine. The vocals are incredible, but I think the message that's just as important is that of friendship, support and love."