"It was hard to read her and I guess I just wasn't sure when [initiating sex] would be okay," he said.
"So it kind of got to a point where she was like: 'Well, why are you taking so long in the shower?' I was like: 'Well, I was you know, doing my thing as a man'.
"And she goes: 'Well, why would you do that? You've got me here,' and I was like: 'Wait, what? I didn't know that was an option'."
Brent said that this awkward exchange was the "only reason" he even knew sex with Tamara was a possibility because "reading her was difficult".
Brent said he had a glimmer of hope for their relationship after becoming intimate, but their arguments spiraled out of control.
"After it we were kind of laughing and getting along so it looked like [the relationship] was going to a better level after that," he said.
Brent went on to admit that intimacy "didn't happen too many times after" their first encounter.
Brent's candor about his sex life comes after he admitted to planning his dramatic walkout at the final vows, where he dumped Tamara, threw his palm cards on the ground and walked off.
"I'll be honest, I planned to drop the cards. I'd had enough and I was ready to walk away and make a statement that she needed to understand," he told The Handbags podcast.
"I had taken shot to shot from Tamara and I wanted to say my piece and walk away. It took me a week to write that speech."
The couple's inevitable breakup, where Brent called Tamara "vindictive, spiteful and self-absorbed" came after months of fighting.
Tamara copped flak from viewers for her judgmental remarks about Brent's career in the hospitality industry.
Brent's candour comes amid rumours he is now romantically involved with co-star Ella Ding. The pair have been spotted hanging out regularly since the show's finale aired.
He addressed the rumours on Wednesday, telling 9Entertainment: "There is an attraction, yes, and there is great chemistry."
The hospitality manager believes he and Ella would have become a successful couple had they been matched in the experiment.
"We spoke about if we were matched, would things be much different, and 100 per cent. I think we'd probably still be together," he said.
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