Liam Payne's highlight of the last week was not releasing his debut solo single but seeing his son Bear smile at him in the bath.

Liam Payne

Liam Payne

The One Direction star - who, along with his four bandmates, went on hiatus in 2015 - became a father for the first time when his girlfriend Cheryl Tweedy gave birth back in March and Liam, 23, admits becoming a father is the "greatest thing in the world" and even tops the excitement of unveiling his new song 'Strip That Down'.

Speaking in Facebook Live fan Q&A, he said: "Fatherhood is the best thing ever. It's been nice. The highlight of my day was when he smiled at me in the bath. Baby Bear is amazing. He makes me smile every second of the day. It's great. It's the best thing in the world being a parent. It's the greatest thing in the world. You hear a lot of parents saying there isn't anything like it and I agree."

Previously, Liam revealed he had planned a mini 1D reunion with Niall Horan, Harry Styles and Louis Tomlinson, to celebrate Bear's birth but things didn't exactly go to plan when Harry couldn't make it.

He said: "Do you know what, I'm doing some sort of like, it's like the man's equivalent of the baby shower. It's the head wetting thing. I've had to put it off for a little bit because of work things."

During his Facebook Q&A, Liam encountered a few technical glitches and joked it's because now he's a parent he can't modern technology properly.