In the offices of Liam Payne's management company, just north of Soho in central London, there's a bottle of Bacardi inscribed with his name.
It was sent as a gift, after the singer immortalised the drink in his hit single Strip That Down. According to the lyrics, which he co-wrote with Ed Sheeran, he mixes it with Coke and "sips it lightly".
There's just one small snag, says Payne: "I don't think I've ever drunk Bacardi".
"When I was younger, I went straight in on the whisky," the star says. "I tend to pick my poison early, then I stick with it until it bores me."
In fact, shortly after Strip That Down was released in 2017, Payne gave up drinking altogether after his lifestyle became "a cause for concern".
"There were a couple of very dark years of me going through extreme peril with different mental health things," says the 26-year-old. "I just didn't know where I was going to end up."
His drinking started to get out of hand while he was on tour with One Direction - the hotel mini-bar becoming a source of solace as he came down from the adrenalin high of playing for 80,000 screaming fans.
But even when the band went on hiatus, the habit continued. "It was very erratic behaviour on my part - I was partying too hard," says the star, who'd always been cast as the "sensible" member of 1D.
"It was a tough little time. My family were very worried."
Eventually, there came a point "where I realised I needed to hit the reset button and take a break," he says.
"I was coming off the back-end of a break-up, so I was dealing with all sorts of emotions that I hadn't dealt with in a long time because I was always covering them up - heartbreak, nerves, all sorts of things.
"I'd gotten too used to this rhythm of life; of using alcohol and different things to mask my feelings, or get me through. So I just needed to prove to myself that [drinking] wasn't the issue for me."
He doesn't say it explicitly, but the switch to sobriety coincided with the birth of his first son, Bear, with fellow pop star Cheryl Cole in early 2017.
The star had always wanted to be a father, but says he struggled to adapt to his new role.
"I'd built it up in my head so much that by the time Bear was born, it was impossible for me to ever match the feeling I thought I'd feel - which is crazy," he says.
His solution was to become a cook. "Thinking logically, I was going, 'Right, if I'm feeding her and she feeds him, then I'm taking care of the family'. Because that's what dads do."
'Success gets the better of you'
After months of rumours, Cheryl and Liam confirmed their split in July 2018, but they continue to share the responsibility of raising their son, who turns three in March.
It means he has to jet "in and out of the country as much as possible", but he seems content to divide his time between super-stardom and domesticity.
Is that why it took two years to translate the success of Strip That Down into a debut album?
Actually, no. It was that song's phenomenal, and unexpected, performance (it's still the biggest-selling solo song by any of the former One Directioners) that threw Payne's plans into disarray.
"Strip That Down was such an amazing thing to happen - but sometimes success gets the better of you," he says.
"It took the best part of nine months to get to number one in America - and for that whole period, people wouldn't put any other songs on the radio. So it was a really weird time. We got stuck with one song for so long that it really prolonged the process of making the album".
It was especially strange for someone who was used to writing and recording entire albums in six weeks or less.
"Writing for One Direction was a different process because you knew what the kids wanted," says the star, who co-wrote about 50% of the band's last two albums.
"I love those songs - don't get me wrong - but I knew why I was writing them and I knew what I was writing them for."
Ultimately, Payne realised that getting more time to work on his debut album was "a luxury" and he allowed himself to "sit back and enjoy the process for once".
Recording sessions took place around the world, with A-listers like Ed Sheeran, Ryan Tedder and Charlie Puth. In total, the album credits a staggering 72 composers - and Payne likens the writing process to "speed dating".
"Sometimes it was difficult because I'd get one or two days in the studio with someone that I don't know and I didn't really want to share an awful lot of private stuff with them," he says. "It's almost like the first day of school every day."
His experiences in One Direction helped him be more assertive during sessions; and he turns out to be a studio geek, marvelling at piano sound on Selena Gomez's Lose You To Love Me, ("they've recorded it so close, you can hear the hammer hitting the strings") and the textural painting in Billie Eilish's Everything I Wanted ("when she sings 'I'm underwater'and they tweak her vocal so it sounds like she's disappearing, it's like Disneyland").
But as the album came together, he gravitated towards the albums he grew up with - Usher's 8701, Justin Timberlake's Justified and Chris Brown's self-titled debut - shaping his solo career around a sleek, efficient brand of R&B.
There's a thread of sadness running through the album - "Heart meet break, lips meet drink / Rock meet bottom, to the bottom I sink," he sings at one point - informed by his recurring bouts of depression, and his high-profile split from Cheryl.
"I'm an absolute expert on heartbreak, it would seem," he says. "I think, for me, it was easier to write from a sad place, because the feelings were a little bit more raw. Happiness is hard to fathom, I think."
'My sexuality is not your fetish'
But it's one of the album's more explicit songs that generated headlines - and for all the wrong reasons.
Both Ways is a late-night slow jam that details a sexual encounter with two women. "My girl, she like it both ways," Payne sings over a ringing trap beat. "She like the way it all taste / Couple more, we'll call it foreplay / No, no, I don't discriminate."
Within hours of its release last week, the track was being criticised for reinforcing harmful stereotypes that bisexual women's sexualities exist for the gratification of men - a fetishisation that can have violent, real-world consequences.
"I'm sick and tired of people thinking my sexuality is made for threesomes," one person wrote in a tweet, adding: "Bisexual women are NOT for your sexual fantasies." Another Twitter user simply declared: "My sexuality is not your fetish."
So far, Payne hasn't responded - but when we spoke last month, before the furore erupted, he said Both Ways was his "favourite song" on the record.
In his explanation, the lyrics are about being open to new experiences and different sexualities, as we emerge into a new "world of 'love is love' and people becoming much more understanding about the way love is - and rightly so".
Payne indicated that the song had originated with one of his co-writers, adding: "I don't know who in the studio had actually been in this situation, because I certainly haven't, but it was an interesting song to write."
Whether or not he addresses the criticism, the song is a blot on his copybook; and a rare mis-step for a singer who's always strived to be on the right side of public opinion.
For a self-confessed perfectionist, its bound to sting; but several times during our discussion, Payne says he's trying to learn from his mistakes, rather than punish himself for making them in the first place.
"My life is super-complicated," he says. "I've got a two-and-a-half year old son, an ex-missus and all sorts of different things kicking off, so I have to drill these messages into my head."
All things considered, would he prefer not to have auditioned for the X Factor all those years ago?
"I wouldn't change it," he says decisively. "I know it's where I'm supposed to be in the world now.
"I was very confused about fame when it all happened; and learning to be a person outside of your job was difficult. But now I feel like I get it. I'm a lucky boy."
Liam Payne's debut album, LP1, is out now on Capitol Records.