Justin Bieber and Lara Stone

Justin Bieber and Lara Stone

Justin Bieber asked married model Lara Stone out on a date.

The 'Baby' hitmaker reportedly "tried to put in the charm" with the 31-year-old model - who is married to British television personality David Walliams - whilst the pair worked on the recent Calvin Klein advert together.

A source shared: "While they were doing the whole Calvin Klein ad, Justin was very forward and asked Lara on a date. He made it look like a joke at first, but then tried to put in the charm.

"It didn't work though as she respectfully declined since she is married. Surprisingly, it didn't get awkward and the shoot went on with out incident."

Meanwhile, the new pictures from the advert are believed to have made the 20-year-old singer "even cockier".

Another source added: "If you thought he was cocky before, you haven't seen anything yet.

"He's definitely feeling himself these days. It's one thing for him to post Instagram pics of himself shirtless, but now that he has done an ad campaign for a major fashion player - and pulling in major revenue for it, too - you can forget it. You can't tell Justin his s**t don't stink."

With his newfound confidence, Justin is reportedly planning on bulking up more.

His trainer, Patrick Nilsson, told HollywoodLife.com: "Justin has put on 20 pounds of muscle and he's still working on it.

"It's a work in progress. We want to put on at least 15 more pounds - he's going to get even bigger. That's the plan."