Shawn Mendes and Justin Bieber. Picture: Instagram

Shawn Mendes has admitted he'd be willing to cough up $500 for Justin Bieber's worn underwear because he's such a huge fan.

The 19-year-old singer has admitted he'd be willing to cough up the hefty sum for the 'Sorry' hitmaker's dirty boxers after he learnt the 24-year-old hunk sold them online. 

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Speaking on 'The Late Late Show' earlier this week, host James Corden told him: "You know Justin Bieber just wears a new pair of underpants every day. I think he then sells them online ... it's a complete 360. Everybody's happy."

Shawn - who has made no secret of the fact he's a huge fan of the 'What Do You Mean?' singer in the past - then replied: "I'd buy them. 

"I'd probably cap it at like $500. Which is still a lot of money."

James, 39, then questioned: "How much would you pay for a pair of my underpants?"

Shawn hit back: "I wouldn't. I'd pay not to have a pair of your underpants. I would pay for them to be as far away from me as possible. Over $500."

The 'In My Blood' hitmaker also gave the comedian an update on his life and explained that he's now moved out of his parent's home and is living alone. 

He said: "I have my own place finally, which at first sucked because cooking for yourself and cleaning your house - it just sucks, until it's actually kind of nice. There's something nice about it now."

But James struggled to believe that he cooks and cleans for himself.

He quipped: "You don't clean your own house."

After much deliberation, Shawn finally admitted that he does enlist the help of his mother but she doesn't mind because she likes doing chores and his laundry.