In “Why”, Shawn Mendes sings about an unspoken attraction between him and another girl; Both of them are attracted to each other but neither of them admits it. In the song, Shawn expresses his frustration over their silence and asks why neither of them breaks the tension and admit how they feel about each other.

Written over soft keys with a guitar in the background, the song follows a smooth pattern, reminiscent of R&B music. Shawn uses a vocoder towards the end of the song, which splits his voice into vocal chords to convey a beautiful but yet sad and vulnerable sound, which fits into the context of the song.

At the time of it’s release, the song was widely speculated to be about Camila Cabello with whom Shawn Mendes has had a burgeoning friendship with since 2015. The two have collaborated on music in the past, with Camila featured on “I Know What You Did Last Summer”. Rumors of the two dating are almost as old as their friendship itself. They both met opening for Austin Mahone at his concert in 2014 and became friends during Taylor Swift’s 1989 Tour in 2015. Both of them have repeatedly denied they were involved.

On December 21st, 2019 during a fan Q&A Shawn Mendes, confirmed this song was indeed written about Camila, whom he has since begun dating earlier that year. When a fan asked him Why did it took so long to tell Camila he was in love with her,
his response was:

I wrote the song “Why”. I was gonna send it to her and I was with Scott and Teddy in the studio. I was gonna send it to her but they told me to wait. I was gonna go see her in New York or something I was gonna tell her in person… "