The DNCE frontman opens up about getting in shape for the steamy photo shoot
Credit: Yu Tsai

Between fronting funk-pop act DNCE and his new gig as an underwear model, Joe Jonas is the complete package!

The singer, 27, is the new face of Guess Men’s new underwear line, and PEOPLE caught up with the singer about getting in shape for the sexy shoot.

Is it weird seeing billboards with your crotch splashed across them?

[Laughs] Yeah, it’s pretty funny. My friends who don’t want to see that … like, my buddy who’s a real estate agent in L.A., his office is right near [the billboard], and he drives by on La Cienega every day. He’s like, “Screw you!” He’s sending me pictures, like, “I hate this. Why do I have to look at this?” I love it. It’s torture for him.

Credit: Neilson Barnard/Getty

When was the first time you saw the ad in person?

I was actually in London. At store, they have a really big sign that says “Joe Jonas for Guess.” I was like, “Woah!” It’s exciting. I wanted to pose with it. People were walking by, like, “That guy kinda looks like the guy on the wall!”

Yu Tsai
Credit: Yu Tsai

The ads look really sexy, but what’s it really like behind the scenes of those shoots? Is it awkward getting greased up and posing like that?

Everyone knows what they’re walking into. It’s one of those funny things where the moments off-camera are when you’re laughing because you’re walking around casually in your underwear talking to people, grabbing catering and whatnot. I’d find myself talking to a friend, and then he was like, “Dude, this is really weird; you’re talking to me, and you’re just in your underwear.” “Oh, yeah, I forgot!” So I had a great team to help out. The photographer is amazing, and he made it really funny and comfortable. Even with Charlotte [McKinney, his model-costar from DNCE’s “Body Moves” music video], it was like a handshake, then we’re holding each other in our underwear. So it was great to be able to work with her — someone who’s really easygoing.

Yu Tsai
Credit: Yu Tsai

You look great! How did you go about getting into shape?

I joined a gym in L.A. that my friends were going to, called Unbreakable. I was only able to start training there for like two weeks, and I loved the place. You could do MMA-style training, boxing, weight-lifting, even just some sort of yoga stuff, and I really thought it was an interesting way of doing the gym. I always do the trainer-client sessions where it’s just you and him, and after a while it’s the same thing. You’re by yourself; you have no one encouraging you, so you’re kind of bored. I wanted to try something else.

I met Ava Knight, who is a boxing champion, and she came on tour with me — I was about to go on tour with Selena Gomez and DNCE for four months — and just busted my ass and trained me with a lot of boxing and, of course, dieting was important; she oversaw that. It’s been nice because I worked out for a while: I had a few months to get ready for it, so the dedication of that is life-changing for you, when you say, “Okay, I’m gonna be standing in my underwear for the world to see!”

Yu Tsai
Credit: Yu Tsai

Your brother Nick has done some sexy underwear shoots, too. Is there any kind of brotherly competition there between the two of you?

We have an open dialogue about stuff like this. He was really thrilled for me, and he was actually at dinner when I got the phone call to possibly do it, and we were talking at dinner [about] if it was something I wanted to do. I was a big fan of Guess, but you know the kind of dedication you need for something like this. And Nick was like, “Dude, you’ve got to do it. This will be really good for you.” So I was glad.

Nickelodeon's 2008 Kids' Choice Awards - Arrivals
Credit: Steve Granitz/WireImage

Looking back at your own style throughout the years, do you have regrets — maybe from your Jonas Brothers days?

There was one time, me and my brothers went to the Kids’ Choice Awards, and I think we hit that age where we didn’t want to be kids anymore, and we were trying to be adults. We wore really oversized suits to the Kids’ Choice Awards, which is just kinda fun and wild and crazy. I’m not saying it was a bad look! It just probably a little bit premature and wasn’t right, exactly. I had an ascot underneath. It was really great. I think we were one step away from top-hats! Which we ended up doing, as well, for a while.