Ivan had forbidden her to sing, but it seems the apple doesn't fall far from the tree, and Joanne will do what she damn well pleases.
She chose Close To You by The Carpenters with Aleks, who loves a sing-along too, joining in.
"Do you mind if a I leave?" Ivan asks Aleks.
"No, I am not letting you leave, no," she says.
"I am getting very uncomfortable," he says. "I'm going to leg it, bro."
The crowd starts to boo when he refuses to stand and join his new wife and his mother, but Ivan is unrelenting.
"You're embarrassing yourself, mate," he tells his mother.
He then tells his wife: "Just sit down babe, it's alright."
But Aleks carries on regardless.
Afterwards he tells her: "You are lucky you didn't lose me there, I almost legged it ... I was about to walk out. She sings at church on a Sunday, but this isn't church on a Sunday."
Outraged that his mother stole his thunder, an embarrassed Ivan starts shouting for shots.
"Where is the Ouza?" he seems to yell at no one in particular.
But it's then that Aleks pulls him for their first serious chat. Her strict Serbian parents are completely against her taking part in the experiment and they to attend her wedding.
"You're parents are here, count your blessings," she says. "I have been in tears every single day because my parents aren't here. I would love for my mum to do that."
"He's got a temper in him, he's Ukrainian, so we are very similar," Aleks tells a guest.
"Ivan definitely has a fiery side, but we are European, we are all hot-headed."
"I really look like a dickhead," Ivan realises, and he apologised for his behaviour.
With all forgiven, they head to bed together laughing at Ivan's tighty whities.