The couple butted heads about a very serious aspect of their relationship: Mike's facial hair.
"I want to talk about this beard," the Queensland electrician began.
"It's really itchy - I feel like I look scruffy."
A dismayed Heidi disagreed, pointing out that many of the other grooms on the show sport thick beards and hinting she likes the look of a rugged man.
But Mike countered: "They've got it kind of trimmed and this is just wild."
The radio announcer begged her husband not to shave, insisting: "That's how I like it, wild!!!"
Heidi eventually conceded it was Mike's body and he can "do with it what you want".
The couple agreed he would ditch the look the following day.
But while things seemed to smooth over easily, MAFS meltdown queen Jessika Power declared that things are not as they seem between Mike and Heidi during Wednesday night's dinner party.
The 27-year-old office administrator boldly claimed Mike planned to dump his bride at the vow renewal ceremony because he finds her "boring".