Did Justin Bieber hit on David Walliams’ wife Lara Stone on Calvin Klein shoot?

Ah, Justin Bieber – he’s a right ol’ scamp that one, isn’t he? Well, it seems he may have been up to some naughtiness on the set of his Calvin Klein shoot in which he starred with David Walliams' model wife Lara Stone.

The pop brat got his inflated muscles and, er, pants out for the shoot in which it looks like someone has stuck a child’s head (aka his baby face) on a man’s body (aka his possibly retouched biceps, pecs, six-pack and package).

Well, if rumours are to be believed, the singer thinks his buff physique means he’s in with a chance when it comes to Lara despite her being married to funny bloke David.

A source connected to the shoot told breatheheavy.com: “He was basically a douche. He hit on Lara several times and she had to stop him, basically calling him out on being just a child.”

Well, David doesn’t seem to be too worried about any competition from Justin as he tweeted a picture of his head photoshopped onto Justin’s body all in the name of LOLZ this week.

And it seems Justin may ACTUALLY have been on his best behaviour on set as a source close to the star insists he would never have hit on Lara.

The insider told heatworld: “Justin would not do that, it’s absolutely ridiculous and totally untrue.”

A representative for Justin declined to comment.

A well behaved Justin? Maybe he’s becoming a man…

GALLERY: Justin Bieber for Calvin Klein