Shawn Mendes has shared his unfiltered opinion about Taylor Swift's boyfriend Joe Alwyn. Mendes has been friends with Swift since he joined her on a music tour in 2015.

Mendes sat down for a lie detector test with Vanity Fair in a video published Monday. In the said clip, the Canadian singer-songwriter revealed his thoughts about fellow singers John Mayer, Harry Styles, and Justin Bieber, as well as Swift's longtime boyfriend Alwyn.

Asked if he still keeps in touch with Swift, Mendes revealed he regularly asks the "Evermore" singer for advice on music. He also recalled that the last time he texted her was about a month ago. However, the "Senorita" singer didn't have much to say about her boyfriend.

When asked if he approves of Alwyn for Swift, he responded, "I've never personally met Joe, but he looks like a sweet guy." 

The lie detector operator then called out Mendes, telling him, "You're not telling the truth. You're being deceptive."

"I'm lying a little bit?" Mendes asked. "Yeah. I mean, he's kind of got a little bit of a villain look about him. He looks like a nice guy but, like, he at any movement could turn into a villain, you know?"

It was then that Mendes started to give his honest opinion about Alwyn, admitting that he "struggles" with blue-eyed people.

"He's got really blue eyes and I struggle with eyes that are blue, you know? Like I find it easier to trust brown eyes," he said, before adding that the "Conversations with Friends" actor talks "way too much about him."

Mendes' revelation quickly became a trending topic on Twitter, earning mixed reactions from fans.

"You know it's funny, Shawn Mendes said more about Joe Alwyn in an interview than Taylor ever has," one fan tweeted.

"How did Shawn Mendes go from 'Joe Alwyn looks like a sweet guy' to 'he kinda looks like a villain' within milliseconds?" another fan tweeted.

While some found Mendes' opinion a bit too funny, some questioned why Vanity Fair even had to ask Mendes about Alwyn.

"Why tf did Vanity Fair ask Shawn Mendes about Joe Alwyn?" one Twitter user wrote.

"Shawn Mendes and his thoughts about Joe Alwyn are irrelevant. Imagine Taylor's feelings about this? Idiot," another user wrote.

Swift and Alwyn have been dating for five years now.

Shawn Mendes Shawn Mendes is pictured on Nov. 10, 2018 in Cannes, Frances. Photo: Valery Hache/AFP/Getty Images