And on Wednesday, the 26-year-old revealed what it was like to get his kit off in front of the camera for the steamy shoot.
Speaking to Nova's Smallzy's Surgery, the 1D singer said he was shocked about just how naked he had to get in the studio session.
You know what, there's a lot more nudity in an underwear campaign than I would of thought there would have been when I signed up for it,' he said, laughing.
While the snaps got plenty of pulses racing, the chart-topper sarcastic joked about his campaign during the chat.
'For me, advertising underwear without the underwear on has got the be the epitome of underwear advertisements,' he said.
Mark then went on to gush over film star Mark Wahlberg, who he trained with at an F45 studio in Los Angeles prior to the shoot.
The 90s New Kids On The Block singer himself is famous for his own underwear advertisements for Calvin Klein.
'I love Mark, he's amazing.... when I got to the underwear commercial, the first picture I saw was a reference of Mark from years ago,' Liam said in the interview.
'He is such a great role model to have in this business, he's also had a really similar lifestyle like the one I've had so far,' Liam said of Mark Wahlberg, who he trained with at f45
'He is such a great role model to have in this business, he's also had a really similar lifestyle like the one I've had so far,' he added.
He went on to say he wanted to re-create a career like Mark's for himself.
'[He] started in a band, then you know he's doing the modelling and the underwear commercial, and obviously he's had an amazing career since,' he said.
In the shoot Liam posed in a pair of tracksuit bottoms designed by the brand, which he teamed with a pair of white trainers.
Liam showcased his rippling arm muscles in the sexy shot, while flaunting his sleeve of various intricate inkings as he crouched down.
The range was shot by iconic fashion photographers Mert & Marcus and styled by renowned Fashion and Creative Director Robbie Spencer.
It is Liam's first campaign for HUGO.
Discussing the collaboration recently, Liam said: 'I knew if I wanted to do something in fashion it should be with HUGO.'
He added: 'They design clothes that guys like me want to wear. Fashion started out as a hobby for me, but I'm loving being part of the creative process.'
© Associated Newspapers Ltd.