Katy & Russell 'Fight All The Time'

Katy Perryand Russell Brand reportedly already fight like 'an old married couple' despite not even getting hitched yet.

Friends close to the Get Him To The Greek actor, who doesn't drink, frowned upon Katy's partying.

SEE PICTURES OF KATY PERRY & RUSSELL BRAND AT THE LA PREMIERE OF GET HIM TO THE GREEK HERE  

The mole revealed: "[Russell] got angry with Katy because he thought she had drunk too much. Perry ended up staying with a friend who has a place in N.Y.C. and Brand went back to the couple’s hotel room alone."

Meanwhile, the I Kissed A Girl hit maker is also said to have problems with ex-lothario Russell's womanising ways with the source stating: "There have always been fights about other women − despite Russell talking about how much he loves Katy all the time,"

The insider claims that shortly before last month's MTV Movie Awards, the couple had a huge bust-up after Katy accused Russell of being unfaithful - causing the couple to arrive at the event separately and sit away from each other.

Perry's 'friend' added: "Katy suspected [Russell] of cheating and it wasn’t the first time, it's a cycle."