Shawn Mendes Insists He and Camila Cabello Never Dated Despite 'Instant Connection': 'We're Just Really Good Friends'

They’re close pals and hit-making collaborators — but were Shawn Mendes and Camila Cabello ever…

“A thing? No, we weren’t, actually,” Mendes, 18, tells PEOPLE with a laugh. “We’re just really close friends. She is one of those people who is just very easy to connect with and still, to this day, is one of my greatest friends. You find that instant connection with people, and she’s one of them.”

Indeed, the “Treat You Better” singer and Fifth Harmony star Cabello’s songwriting spark was evident on “I Know What You Did Last Summer,” their 2015 hit, which peaked at No. 20 on the Billboard’s Hot 100.

“She’s a f—ing great writer,” says Mendes of duetting with Cabello, adding that he hopes they can hit the studio again in the future. “Even if we just wrote for other people, I would be happy to do that because she’s such a thrill to write with and work with.”

Mendes — whose new album Illuminate dropped Sept. 23 — and Cabello, 19, have been plagued by relationship rumors and even endured some on-air teasing from James Corden last year, when the late-night host poked fun at their alleged romance. But the “Stitches” star insists they took it all in stride.

“We don’t take ourselves seriously … so that wasn’t awkward,” says Mendes. “We’re also so close with each other that we could say anything, and it wouldn’t make a difference. And that’s a friendship that you have to hold on to forever.”

Still, he maintains, “We’re not dating — nor did we.”

For more on Shawn Mendes and his new album Illuminate, pick up the new issue of PEOPLE, on newsstands everywhere Friday.

Between Illuminate debuting at No. 1 and a busy headlining tour schedule, one could imagine Mendes has little time for dating. But he says that’s not the case.

“It has nothing to do with the spotlight; I just think I haven’t found the right girl,” says Mendes. “If I did, I wouldn’t make my life get in the way of it because I don’t think love, if it’s real love, has boundaries. You work through things: distance, fame, whatever it is, you work through it.”