Zima Anderson and Matthew Mitcham suffered a humiliating encounter during their toilet break on Tuesday night's episode of SAS Australia.

The Neighbours actor, 25, and Olympic diver, 35, were forced to go to the bathroom in stalls right next to each other with very little privacy as viewers at home watched.

But there was one thing in particular that the blonde beauty was worried about - her fellow SAS co-stars accidentally looking over the side of her cubicle. 

At five feet tall, Zima couldn't sit down on the toilet without her feet lifting completely off the ground, making it impossible to see her legs under the door. 

As Matthew finished up his business and stood to pull up his pants, Zima expressed her fear about others 'seeing her vagina'. 

'It probably looks like there's no one in here so it's kind of awkward if one of the guys come over and looks over the side. I don't want people looking at my vagina,' she said. 

'How is anyone going to see your vagina when you're sat down?' Matthew asked with a confused expression. 

Barely visible in her cubicle, Zima replied: 'They can still kind of see it.' 

'How high is your vagina?' Matthew exclaimed, to which Zima said: 'Like, at my bellybutton, how high is your vagina?' 

It came just moments before two high profile SAS Australia contestants walked out on the show during Tuesday's dramatic second episode. 

Balinese princess Lindy Klim and convicted drug smuggler 'Cocaine Cassie' Sainsbury both decided to call it quits. 

Lindy struggled through the second day of challenges and admitted she was 'completely out her comfort zone' but said she was proud of her efforts regardless.  

Earlier, Lindy had a rough time during the helicopter challenge, and called herself a 'Karen' who needs her comforts. 

Cassie also departed, after being unable to face a challenge in which she had to crawl through a tunnel filled with water.

She worried that the cold, dark, confined space would remind herself too much of her stint in a Colombian jail, and refused to see it through.