With a recent pair of high-profile network performances on Sunday night's (May 20) Billboard Music Awards and the season finale of the wildly popular 'Dancing With the Stars,' it's hard not to notice a more trim and toned Kelly Clarkson. What is the catalyst behind the the weight loss? According to a recent interview with PEOPLE, her new man is a driving force behind her more slender figure.

"I would love to say that it had something to do with my work, but it doesn't," Clarkson confesses. "I have a boyfriend, and if I'm being completely honest, no one likes to be not toned when you are dating someone."

Who is this mystery man? According to many sources, Clarkson has been dating Brandon Blackstock, son of her manager, Narvel Blackstock, and stepson to her celebrity BFF, Reba McEntire. The two do share a trainer, but do not work out together.

"I tone whenever I want, and I chose to now because my boyfriend and I are both really into it, but we don't work out together," says the 'Mr. Know It All' singer. "We did that once and I didn't like huffing and puffing. "I didn't like looking all red and gross, so I don't do that."

The two share an interest in fitness, but music is what initially drew the new couple together. "We both love music so we go to shows together," Clarkson says of Blackstock, who also happens to be Blake Shelton's manager. "I am just more active with him."

Personally, Clarkson seems to be at the top of her game. Professionally, the singer is riding the same high. Her current pop single, 'Stronger (What Doesn't Kill You)' recently became her third No. 1 pop single, as well as her best-selling digital single to-date. As the singer gears up for the release of her next pop single, 'Dark Side,' Clarkson is enjoying a bit of country success. An exclusive country remix of her smash 'Mr. Know It All' is currently sitting at No. 28 on the country singles chart.

Click here to view show dates for Clarkson's summer co-headlining tour with the Fray.