(Cover) - EN Showbiz - Justin Timberlake and Mila Kunis were seen being incredibly flirtatious in London this week, it has been reported.

Justin and Mila are in the British capital this week to promote their movie Friends With Benefits. The pair are both staying at the Dorchester Hotel, albeit in separate rooms, and have been seen getting cosy with each other around town.

On Wednesday night a couple of hours before midnight, Mila took a trip down to the hotel bar, The Promenade, where she began to perform some classic love songs. Justin greeted her just ten minutes later and belted out some Frank Sinatra tunes himself.

The pair then headed out together for some dinner. While enjoying dim sum in between giggles at China Tang restaurant, the pair could not help but stare at each other.

"Justin couldn't take his eyes off Mila," an onlooker told British newspaper The Mirror. "He was hanging on every word she said, and laughing a little too heartily at her jokes. But it was all very sweet."

Justin and Mila have been travelling all around Europe together, promoting their new film. (C) Cover Media