The See You Again hitmaker teamed up with Selena last year (15) for his song We Don't Talk Anymore, and the pair has repeatedly been linked as lovers ever since they posted a video on social media app Snapchat in January (16) after the Golden Globes.

Selena denied the reports at the time, telling, "We're not (dating), that's for sure", but the status of their relationship hit headlines once again earlier this week (begs28Mar16), amid new claims suggesting they have been enjoying a secret fling for months.

"It's not serious, but she's super into him," a source told

Charlie was quizzed about the latest romance allegations during an appearance on America's The Tommy Show on 94.7 Fresh FM, and he was adamant there is still no truth to the rumours.

"We're friends, and I'm very happy to have collaborated with her," he said, according to Entertainment Tonight. "She's a really awesome singer."

"We did a song together and people think that there's more, but we just musically collaborated," he added. "I'm going on tour with her. She's gracious enough to let me come on a couple dates with her."

The cheeky hosts teased Charlie about his use of the word "dates", prompting the 24-year-old to laugh and clarify, "Music...! Tour dates! Yes, tour dates."

Continuing to gush about Selena's talents, he concluded, "She's really, really awesome and she's a really, really fantastic singer and kills it in the studio, and I love working with singers who just know what to do right away."

Selena is set to kick off The Revival Tour in May (16), with Charlie joining Justin Bieber's ex as her opening act in Anaheim, California in July (16).