Housemates enjoy Sunday's ceremony. Big Brother, Channel 4, nightly.
Four Big Brother housemates are facing eviction for failing a secret task.
Mario Marconi and Stephanie McMichael had to pretend to be a couple to hide Mario's real romance with fellow housemate Lisa Appleton.
The remaining contestants guessed the pair were faking an hour after the couple supposedly got married inside the house.
The wedding took place on Sunday afternoon. A fourth housemate, Luke Marsden, was also in on the secret.
Mario and Lisa have been dating for three years
Stephanie, 19, wore a crisp, white gown for the ceremony, while Mario, 42, donned a tuxedo and a blue waistcoat.
But an hour after the couple tied the knot, Big Brother announced there was a secret couple living in the house and housemates had one minute to guess who it was.
After a series of rows and bickering, blind radio producer Michael Hughes gave the correct answer.
The shock announcement delighted Alexandra De-Gale who had already contested the wedding as "a sham".
The correct guess guaranteed that Mario, Lisa, Luke and Stephanie are up for the first eviction and will face the public vote this Friday.
"This has got to be the twist of the century," Michael said after the truth was revealed.
Stephanie jumped into the swimming pool still wearing her wedding dress and told housemates she had found the task so hard she had repeatedly cried in the diary room.
Mario and Lisa were delighted that they no longer had to keep their romance under wraps but Luke was unhappy about being up for eviction.
"The reason why we're on the chopping block now is because of Stephanie," he said.
Thai massage therapist Kathreya Kasisopa, 30, is the current favourite to win the competition, according to Ladbrokes.