They've shared one of the most tumultuous relationship of the season. 

And the future of Alana Lister and Jason Engler's TV marriage isn't looking too bright, thanks to a new trailer for Monday night's final vows episode.

The emotionally-charged clip begins with footage of Jason nervously adjusting his suit in the mirror as he prepared to meet Alana at the altar.  

'I'm scared of telling Alana how I feel and her not feeling the same,' he added. 

Meanwhile, Alana was seen looking apprehensive as she got dressed in a separate room. 

'I don't want to break Jason's heart,' she said, picking up her white gown from the bed. 

The couple finally meet at a beachside altar, but the idyllic scenery does little to quell the obvious tension between the on-and-off lovers. 

'I feel that we are in different stages of our lives,' the schoolteacher said, as Jason's face flushed red with emotion. 

While it's unclear whether Alana will dump Jason at the altar, the trailer's final shot appears to suggest the couple will part ways by the end of the episode.  

In the footage, a dejected-looking Jason is seen walking alone on the beach with his shoes in his hand, staring off into the distance in a moment of apparent sorrow. 

Alana and Jason's marriage was rocked by a slew of arguments this season, most of which revolved around Jason's friendship with 'villain' Bryce Ruthven. 

While they did share an active sexual relationship, the couple struggled to take their bond to a deeper level during the experiment. 

Married At First Sight continues Monday at 7.30pm on Nine.