Liam Payne changed his son's first nappy.

The former One Direction hunk was forced to jump straight into fatherhood when his little boy Bear was born at the end of March as he was put on ''diaper duty'' for the first day because his partner Cheryl was ''so tired'' after a long, gruelling, labour.

Speaking during the interview with SiriusXM, he said: '''I did all the first day's worth of nappy changes, because [Cheryl] was so tired, she slept more or less. All day, there was no poo. I was like this is great, I can handle this.''

But then the 33-year-old singer said she wanted to have a go at changing her son's bottom for the first time after the tiny tot woke up screaming at 5am.

He explained: ''I was like go on babes, this was her first ever nappy change. So he poos for the first time, of course he does. Secondly, sprouts off [starts weeing]. I'm looking at him thinking this didn't happen to me all day. That's so unfair. She had to give birth to him and she was the one who got weed on first.''

Liam is currently in the US promoting his debut solo single 'Strip That Down' and admitted, although he was sad to leave his family in UK, he was excited for an In-N-Out burger.

He joked: ''I left my wife and child at home and I was straight out to In-N-Out Burger.''

Meanwhile, although Cheryl has remained tight lipped on her life as a new mother since the arrival of Bear, Liam couldn't wait to start gushing about his new bundle of joy and revealed earlier this month that it was his partner who picked out the little one's unusual moniker.

He said at the time: ''It was like an internal battle. I wanted a more traditional name and she wanted a name that was more unusual. And the reason she chose Bear in the end was because Bear is a name that when you leave a room, you won't forget. And I like that.''