'Married At First Sight UK' teases heartbreak in reunion episode

Morag didn't look too happy at the reunion. (Channel 4)

Married At First Sight UK may have ended on a high with all five remaining couples choosing to stay together, but a teaser from next week's reunion episode has left fans worried that some of them may have already split.

Matt and Dan, Marilyse and Franky, Amy and Josh, Luke and Morag, and Tayah and Adam all chose to renew their vows in the E4 show's final, with some of the decisions coming as a surprise to viewers.

Read more: MAFS UK star Morag slammed by viewers for U-turn on Josh DMs drama

However, an advert for a reunion episode shown at the end of the final included tense and tearful scenes for at least two of the couples, leading viewers to believe that some of the relationships may not have stood the test of time.

Married At First Sight reunion
Will Luke and Morag have stayed together? (Channel 4)

Monday's episode will see all of the series contestants gather together for one last time to tell the experts how life has gone for them outside of the experiment - and it looks as though things have been tough for both Luke and Morag, and Amy and Josh.

Teaser scenes showed Morag and Luke sitting on the interview couch as a tearful Morag shouted at her husband: "I don’t even know who you are right now!"

Amy also looked emotional as Josh was shown telling the experts: "One minute we’re good, one minute we’re bad."

Married At First Sight reunion
Jordon and Josh both have a lot to go over. (Channel 4)

One viewer tweeted: "Not surprised to see Morag & Luke are already arguing at the reunion."

Someone else predicted: "Luke, Morag, Josh, Amy will NOT be together come reunion Monday."

Both couples had a tricky time getting to know each other as Morag tried to change Luke to fit her ideal of the perfect man, and Amy struggled with Josh's reluctance to open up while he complained about her temper.

It had also been a shock to many fans to see Marilyse choose to stay with Franky, who had shown signs of controlling behaviour throughout the series.

Read more: MAFS UK star on what viewers don't see

Monday's reunion will not only contain drama from the couples who made it to the final, as explosive bride Nikita, cheating spouses Megan and Jordon, and emotional groom Bob will all return, too.

E4 finally aired the last episode in the series on Friday night, a day later than planned after the channel accidentally broadcast the penultimate episode two days in a row on what should have been Thursday's series finale.

Married At First Sight reunion
The reunion is sure to be full of drama. (Channel 4)

Disappointed fans complained at being shown an old episode which later turned to a blank screen and was eventually switched for a repeat of First Dates.

This week has seen a number of All 4's channels experience broadcasting issues with programmes dropping off air for some viewers.

Watch: Married At First Sight contestant reveals he'd kissed another bride