After group, a shocking nighttime reveal of infidelity pushes one of our couples to the brink of ending their relationship. Will their housemates be able to talk them off the ledge? This week's lesson is about communication and Steve needs to find out how our twosomes fight when the gloves come off and the rules no longer apply. Things get messy as the couples hurl insults and green slime at each other and one couple takes this challenge way too far. And later, when the pairs are tasked with moving furniture into their own bedrooms, one explosive comment leads to a vicious war between two of our couples.