Lachlan's future on The Super Switch hangs in the balance this week after he's pushed to his limit.
At the end of tonight's episode, we saw him tell the camera that he was "struggling" and "wanted to go home", just hours after arriving in the Northern Territory on the group's getaway.
But it wasn't the harsh living conditions that sent him into a downward spiral. It was the sleeping arrangements between him and switch partner Neesha.
"We were told that we had no choice but to sleep in the tent together," he reveals to TV WEEK. "It was the rules. So I said, 'I quit'. I'm not going to do that and I knew Miranda would be devastated. It's a trust thing. Neesha was upset too."
Lachlan said he was at "tipping point".
"I felt like it [the experiment] was pushing the boundaries too much and I didn't like it," he says. "And I was missing Miranda, too".
Up until now, Lachlan has had a relatively easy run – he and switch partner Neesha have got on well.
But he says there's "no attraction" between them.
"I just saw her as a mate," he reveals.
"It was good knowing we were both there for the right reasons. I'm naturally a shy person when I meet new people, so it made it easier in that aspect. The whole point of the experience was to get along with your partner and try to find yourself in them. We have the same morals."
The Super Switch, Wednesday, 8.30pm, Channel Seven