Jon Bon Jovi says being a grandfather is "crazy but ... wonderful".

The Bon Jovi frontman, 63, became a grandad for the first time over the summer when his son Jake Bongiovi, 23, and his wife Millie Bobby Brown, 21, adopted a baby girl - and the rocker has insisted she fitted into the family straight away.

In an interview with influencer Bunnie XO, shared on TikTok, he said: "It's crazy, but great. Wonderful. They adopted a girl, we met the baby obviously and immediately that becomes your grandchild, you know what I mean?

"Your baby. It's beautiful. I want to see pictures, like, every other day. I'm that pain in the butt guy already and, yeah, it's cool."

Bon Jovi went on to insist he supported the marriage even though the pair are "very young" and he's adamant it's "working out".

He said: "They got married very young but we blessed it because we get it - you know, they're sorta mature beyond their years.

"She comes from a family where her parents are still together and they married very young. Her and Jake fell in love and we just thought OK, we'll support this and it's working out."

Millie and Jake - who married in 2024 after three years together - revealed on 21 August that they had become parents for the first time.

They wrote in a joint post on Instagram: "This summer we welcomed our sweet baby girl through adoption. "We are beyond excited to embark on this beautiful next chapter of parenthood in both peace and privacy. And then there were 3. Love, Millie and Jake Bongiovi (sic)."

Millie previously admitted she was looking forward to the challenges of parenthood and had always hoped to be a young mother.

During an appearance on the Smartless podcast, she explained: "My mom actually had her first child at 21, and my dad was 19. And you know, it's been my thing since before I met Jake. Since I was a baby, I told my mom, like, baby dolls. I wanted to be a mom just like the way my mom was to me.

"And my nan, my grandmother is, she was a huge part of my life. And so, yeah, I mean, Jake knows how important it is to me and, of course, I want to focus on really establishing myself as an actor and as a producer, but I also find it's so important to start a family for me personally."