Justin Bieber better watch out, The Wanted’s Siva Kaneswaran is after you!

Justin Bieber clearly likes to have bromances with British boys — not only is he BFFs with One Direction's Zayn Malik, he's also got erm, pretty close to The Wanted's Siva Kaneswaran.

Last week Justin Bieber admitted his favourite 1D member was Zayn and now, last night it's emerged he bonded with Siva Kanesawaran.

[Related story: Justin Bieber and Zayn Malik are BFFs]
[Related story: Justin Bieber teases new Boyfriend video]

As The Wanted storm the States, they appeared on The US version of The Voice last night along very well with Justin.

After the Canadian star teased fans with a preview of his video for Boyfriend, it appears he succumbed to some mischievous behaviour, The Wanted style.

And it was al to do with slapping private parts, we thinkg.

Max George tweeted: "Great to see @justinbieber at the Voice...his jab to @SivaTheWanted 's balls was legendary!!"

The in-joke was quickly retweeted by Justin — but what exactly went on remains a mystery.

The Wanted are famed for being pranksters /WENN

Siva's summary of events was pretty brief… he tweeted: "The voice was feckin amazing! #thewantedonthevoice"

We can't imagine this is the end of it, The Wanted are famed for being pranksters although the laughs were at their expense last week.

The band were charged with kidnapping an 11-year-old fan in an elaborate prank set up by MTV show, Punk'd.

Max said: "We got pulled over by the police and they said there was a complaint against us about a girl going missing, and all of a sudden she appeared from the back of the car. It was pretty intense."

"I was like, 'This must be a joke,' but then they left it going for nearly two hours and then I thought, 'It might not be'."

Justin Bieber should really watch his back, we imagine The Wanted's revenge will be sweet.