Justin Bieber says he and his wife Hailey have sex "all day". Picture: Reuters

Justin Bieber says he and his wife Hailey have sex "all day".

The 'Love Yourself' hitmaker - who married the 23-year-old model in 2018 - has opened up about their love life and hinted things can get "pretty crazy" when they get to spend some time together.

During an intimate performance and Q&A at Indigo at The O2 in London on Tuesday night, he said: "So when I'm with my wife, we like to ... You guys can guess what we do all day. It gets pretty crazy. That's all we do. We like to watch movies, we like to Netflix and chill - but we definitely do more of the chilling."

The 25-year-old singer also revealed he's loving married life, although he was keen to point out their relationship still has its challenges.

He added: "Being married is so awesome. I'm telling you, but don't get it twisted, marriage is not easy.

"It's something you got to work for. If marriage was easy, everyone would do it really fast. Everyone would just do it.

"So you guys want to have children, and want to get married, just know that it takes work every day.

"You've got to choose to be patient with that person, love that person, be kind to that person and that takes work. It's powerful. It's really, really incredible."

The loved-up couple tied the knot in September 2018 on the same day they acquired their marriage license, but didn't hold a formal ceremony with family and friends until a year later.

Hailey recently revealed they decided to wait to hold their ceremony because it would have been "hectic and stressful" to try and plan a wedding when Justin was battling a series of mental and physical health problems.

She said: "When we first got married, we were just figuring out our life together. I felt like putting a wedding in the middle of all of that would be really hectic and stressful."