Miley Cyrus play fights with Avril Lavigne on Instagram video

She is arguably the most famous singer in the world right now.

And Miley Cyrus seems determined to keep it that way.

In new pictures and a video posted to Instagram, Miley is seen attacking fellow pop star Avril Lavigne after the pair argue about which of them is 'the most famous person in Canada'.

In the video, posted by Miley, 20, on Tuesday, she wears a Marijuana onesie.

She is seen reading a magazine with a paper stuck to the front showing Avril, 29, with the words 'the most famous beautiful and popular in Canada' scrawled in black pen, as well as 'I heart' and a picture of a marijuana leaf.

Miley, who is currently in Canada for her Bangerz world tour, looks indignant that she isn't given the 'most famous' title.

'I mean I'm in f**king Canada,' she says.

Avril then walks in and strides up to the star.

'Oh hey Miley, I'm actually the most famous person in Canada,' says the Ontario native. 

Miley then jumps up and protests, stating, 'I'm the most famous person in Canada, you dumb f**king b**ch'.

The pair then start play fighting. 'F**k you,' shouts Miley. 

Avril famously came out in support of Miley's controversial VMA performance last year, stating:

'It's actually really funny cause my managers also manage her. She is doing her thing right now and she is kicking a**, so good for her.'

Kristen Stewart & Robert Pattinson Have Fight On His Birthday

Oh no! Rob and Kristen reportedly had a huge fight on his birthday, May 13. Are they heading for a split?

Kristen Stewart and Robert Pattinson have certainly had their fair share of ups and downs throughout their relationship — most notably with K-Stew’s cheating scandal in July 2012 — but after the Twilight actress was spotted looking very glum on Rob’s birthday, May 13, we’re a bit nervous the twosome may be heading for splitsville!

Kristen, 23, was spotted at a friends house on the afternoon of May 13, arguing on the phone. According to a report by X17 Online, it appeared as though K-Stew and Rob, 27, were breaking up.

“Kristen was pacing back-and-forth in her friend’s apartment, smoking. She looked really upset, talking on the phone for almost an hour — I’m guessing she was talking to Rob. She was really animated, like she was trying to explain something. She was getting frustrated and seemed very emotional,” a photographer tells X17 Online.

After ending the heated phone conversation, Kristen and her friend drove to another friend’s house, where they ended up talking in the car for almost 45 minutes.