Liam Payne says he and Cheryl Tweedy are "basically" married.
The couple - who welcomed son Bear together earlier this year - have no immediate plans to wed but Liam insisted they are "basically at that stage".
And Liam revealed that dating Cheryl, 34, makes him feel like "the biggest winner".
He told the Daily Telegraph: "It's a ridiculous place to be in. She's even more amazing than I thought. I was watching her do 'Fight For This Love' [her debut solo single, from 2009] when I was a kid, and now we're together with a kid. I feel like 'I'm X Factor's biggest winner.
"I feel great about what's going on in my life. I'm extremely lucky. I feel like I'm in a comatose dream. I'm like, 'when did I last bump my head?' because I can't believe this.
"We think about the same things. She understands what my life is like. She knows what it's like to sit on the Graham Norton couch [or] we can talk about her L'Oréal work. It's not that we're 'a brand' as a family, but we can help each other."
And Liam revealed he even struggled to write new music because he was so happy with Cheryl.
He explained: "I had a bit of a problem formulating what was going on in my brain into the music at first, because I was so content with everything in my personal life. It's easy to spill your guts out on a ballad. But I was thinking, 'Oh God, I'm really happy - what am I going to write about?!'"
However, he hasn't always been so happy and Liam admitted that he partied hard during his One Direction days, especially after he was given the all-clear to drink alcohol from the age of 19 after being diagnosed with a scarred kidney when he was younger.
He said: "I wasn't happy. I went through a real drinking stage, and sometimes you take things too far. Everyone's been that guy at the party where you're the only one having fun, and there were points when that was me. I got to 13 stone, just eating crap. I got fat jibes, and it affects your head. I have nothing to hide about it.
"It was like a musical university. We were pretty reckless, but I got it out of my system. I had my fun."