Married at First Sight fans react to Sean and Jo mismatch: "Awkward!"

Married at First Sight Australia delivered one of its biggest ever mismatches when the experts pitted together Jo McPharlin and Sean Donnelly on Tuesday night's episode.

*This article contains spoilers about Married at First Sight Australia season five*

The E4 series attempts to set people up on the ultimate blind date: they meet for the first time at the altar as they're getting married, but it wasn't a happy ever after for single mum Jo, 41, and pub manager Sean, 41.

In fact, the experts could not have made a bigger mistake. Sean, sweating and blinking furiously, said: "S**t!" at the altar when he realised what he'd got himself into.

He made an understatement when he said the experience was "a lot more difficult than I envisaged".

Married at First Sight Australia viewers were alternately transfixed and traumatised by the awkwardness of the couple's union. This fan tweeted that Jo was just not reading her new husband at all: "A blind man on a galloping horse can see Sean is not comfortable at all."

This Married at First Sight viewer, like so many, commented on the disparity between their perceptions of each other. "Oh dear, this really is not going to end well."

Another fan posted about the awkwardness of the wedding ceremony. A visibly uncomfortable and nervous Sean "doesn't know if he's coming or going".

"AWKWARD!" was the reaction of so many in the Married at First Sight audience, but it was somehow compulsive viewing and therein lies the series' success.

Sean has had mixed experiences on dating apps and this viewer thought that Sean may have swiped left that time he saw Jo on Tinder.

Numerous fans on social media questioned how the experts came to match Jo and Sean and how differently they reacted to each other.

This fan wondered where the experts got their qualifications. "This is a car crash waiting to happen!"

Sean's best man came in for much praise from viewers for the way he tried to calm down his friend and pointed out Jo's qualities, "even though he knows Jo isn't Sean's usual type".

Find out what happened to Jo and Sean after the cameras stopped rolling in our new update.

Meanwhile, the episode's other couple Mathew Lockett and Alycia Galbraith were the polar opposites to Sean and Jo, in that there was an actual spark between them.