Adam Levine's eldest daughter Dusty is "obsessed" with her new sister Gio.

The Maroon 5 frontman and model wife Behati Prinsloo welcomed their second daughter into the world in February (18), and are getting used to life as a family of four. And while some parents worry about how their first-born will react to a new arrival, Adam admitted during an appearance on The Ellen DeGeneres Show on Monday (07May18) that 19-month-old Dusty is loving every second of being a big sister.

"She's obsessed with Gio, to the point where every morning when she wakes up the first thing she says is, 'Gio, Gio, Gio', and runs into her room - it's really cute. She's totally in love with her," he smiled.

However, Dusty hasn't quite grasped the concept of her little sister being somewhat fragile.

"She's a little rough with her because she doesn't understand that thing yet, so she'll get in her face and do crazy stuff but it's just so much fun," Adam laughed. "Being a dad is the most fun thing on the planet."

The family have a few exciting weeks coming up - with Behati's 29th birthday on 16 May, and Maroon 5's Red Pill Blues Tour kicking off later this month.

Behati, Dusty and Gio will be joining Adam on the road for the tour - a prospect he's unsure about but also looking forward to.

"I always thought of tours as a bunch of dudes in bunks and it's (like a) sleep-away camp, but now it's going to turn into a totally different thing, so I'm going to have to figure that out - I've never had to think about that," he mused. "So we're probably going to have to have a family bus or something. It will be strange. But yeah, it's going to be fun, touring with the kids is going to be fun because it's an amazing experience for them - they get to see the world."