Fifth Harmony's Camila Cabello may not be dating Shawn Mendes, but the starlet recently revealed that the pop singer is important to her, while also discussing the real experience behind their duet.

In an interview with Fuse, Cabello had nothing but positive things to say about Mendes. The singer called the Canadian pop star her best friend and "life coach."

"I can honestly say that [Shawn] is one of my best friends now we talk all the time," she said. "He's my life coach. I'm just so irresponsible about things, and he's always like, 'Camila, you lost your voice because you're not drinking enough water! Are you eating good food?' Whenever I have a crisis, he goes, 'You need to breathe in and breathe out,' and gives me a pep talk."

The two have been busy promoting their duet, "I Know What You Did Last Summer," which Cabello revealed was about a struggling relationship. However, Cabello recently added that the song, which she and Mendes released a music video for on Nov. 20, is very personal, since it relates to an experience of her own.

Cabello explained that she was romantically interested in a guy who liked her as well. Only three days before writing the song with Mendes, she found out from a friend that the guy was trying to become involved with her as well.

"I really liked him a lot, so the inspiration for me was when I found out that he was not involved with just me. I confronted him, and obviously we weren't a thing anymore. That's why I connected to it so much," she added.

Since its release, the song has done well on the top 100 songs on the iTunes Charts, currently in the No. 27 spot. Both Mendes and Cabello have received positive reviews from fans.

On the video's release date, Cabello and Mendes got together to perform the song on "Live With Kelly And Michael," and even though they are both used to getting on stage in front of thousands of fans, their first performance of the duet was nerve wrecking, reported MTV.

"We were so nervous for that, you have no idea. We were like, peeing ourselves. But we think it's safe to say they nailed it," Cabello said.

Check out the official video for "I Know What You Did Last Summer" below.