Who is the Mystery Guest on Big Brother: Unlocked episode 3? Details explored

The mystery guest on Big Brother: Unlocked episode 3, revealed on August 22, 2025, was Rob “Boston Rob” Mariano. Known for multiple seasons of Survivor and an appearance on The Amazing Race, Mariano joined host Julie Chen Moonves, Derrick Levasseur, and Taylor on stage during the live aftershow.

His appearance followed clues teased earlier in the episode, including references to gemstones, tea, and Survivor. Mariano’s arrival led to a discussion about whether he would ever compete on Big Brother and reignited conversations about a potential Survivor versus Big Brother crossover.

Boston Rob revealed as the Mystery Guest on Big Brother: Unlocked episode 3

The clues and reveal

Ahead of Mariano’s entrance, Julie Chen Moonves addressed the audience, noting that one of her favorite parts of the show was the reveal of the "mystery guest" who would soon appear live on stage. She also mentioned that the clues had already been released and were shown once again.

"All right, so we have Amber Gemstones. I thought those were cough drops. Tea, tea, and survivor. So I know who this is. Let's bring this person out," she said.

As the crowd responded, Derrick Levasseur cheered on alongside Big Brother: Unlocked co-host Taylor Hale before Mariano was welcomed on stage. The audience erupted in cheers as Moonves introduced him, saying:

“Now, Boston Rob, everyone knows that you are one of the greatest reality show players in history. You've played survivor five times. You won it once, you met your future wife, Amber.”

During the reveal, Mariano addressed the clues provided. He explained that he liked the clues but clarified that he does not drink tea, adding shortly after that he prefers a "little coffee."

Mariano’s thoughts on competing in Big Brother

The episode quickly shifted to whether Mariano might consider competing in Big Brother. Julie Chen Moonves asked directly if he could handle “three months living in the Big Brother house.” Mariano responded:

“I'll tell you what, Julie. I think you got a shelter over your head. We're eating. However, all summer in here with these lunatics, I don't know.”

This prompted Levasseur to weigh in on the idea of a potential crossover. He told the host that if Mariano returned, he might also come back. Moonves then reacted by saying “Whoa” before cautioning him not to commit too quickly.

Levasseur also raised the idea of Mariano becoming the first Survivor contestant to join the Big Brother house, asking if he could be the one. Mariano did not give a definitive answer, instead leaving the possibility open by saying that they would have to “see” and thanked Julie.

The Survivor vs. Big Brother proposal

The conversation tied into a proposal previously raised during the Big Brother 27 live eviction episode, where Levasseur suggested a hypothetical Survivor versus Big Brother season. In that episode, he said:

“If [Boston Rob agrees,] maybe I’ll come back. ‘Big Brother vs. Survivor.’ I would love to participate in the ultimate CBS reality series showdown.”

Mariano addressed the idea again during his Big Brother: Unlocked appearance. He repeated his concern over the length of the game, pointing out that as long as there is “a shelter over your head” and food provided, it would be manageable, but questioned lasting the whole summer.

To conclude the segment, Chen Moonves emphasized the ongoing invitation, saying:

“Boston Rob, I challenge you. I challenge you. Don't back down for a challenge.”

Stay tuned for more updates.