Big Brother hasn’t wasted any time in toying with housemates as the new batch of TV hopefuls arrived in the house on Thursday night.

The first four contestants to arrive on the Channel 4 show were given a secret mission – which involved one real couple breaking up and another ‘fake couple’ forming.

The reward for completing the task is immunity from the public vote next week – but failure means they will definitely be up for eviction.

First to enter the house were Warrington couple Mario, 42, and Lisa, 40. They were followed by clean-living student Luke, 20, from Wigan, and former Popstars: The Rivals contestant Stephanie, 19, from Liverpool.

Shortly after entering Big Brother summoned the first four contestants into the diary room where they were told about the mission.

Real-life couple Mario and Lisa were told that from that moment on they were no longer a couple. Instead Mario and Stephanie were instructed that they had to pretend that they were a couple. Lisa was told that she must pretend she had only met Mario for the first time that evening.

If the group succeed in their challenge they were told they would be immune from the first eviction.

Big Brother quipped: ‘Stephanie, you make a lovely couple.’

Before the next housemate arrived the four made hasty plans as to how they might fool the others.

Host Davina McCall later revealed that Stephanie and Mario will have to go through a wedding ceremony which they think is real as part of the task.

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