Paul Archuleta/Getty; Rochelle Brodin/Getty for OPPENHEIM GROUP
While speaking with PEOPLE at the launch of 1060 App on Thursday in West Hollywood, the luxury realtor and Oppenheim Real Estate president, 45, discussed Quinn's absence in the upcoming sixth season of the Netflix reality show.
"This is our first season without her, and she's a big loss because she's made for reality TV," he said. "We stay in touch, just not so often. Just mostly over Instagram or a text here and there."
Explaining his previous anxieties around Quinn not being on the show, Oppenheim explained: "But I got to say, I might have had a little bit of concern going into season six, but I have no concern coming out of season six."
"I'm really proud of this season," he added. "I think everybody stepped up, and it just ended up being unexpectedly an awesome season. So, all concerns have been completely diminished."
Teasing more about season 6, Oppenheim said: "We were a few weeks into filming, and there was absolutely no drama. I was like, 'Oh, s—. OK, maybe we're going to have a mellow season.' Honestly, I was really kind of pleased about it. Then, some s— hit the fan just unexpectedly. So, I actually think that this season's going to have as much drama as the other seasons."
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"Yeah, it just came out of nowhere, but it was pretty rough for a few weeks in the office," Oppenheim shared. "So, I think that it's probably going to be entertaining for people even though it was a little difficult for me and my brother (Jason Oppenheim)."
Noting that the tensions have arisen between "people that we both care about a lot," Brett said one particular scene was "tough."
"We were in Europe when it started to hit the fan, which was kind of nice in some ways because we didn't have to deal with it directly, but it was also a little bit troubling because we weren't there to try to smooth things over," he explained. "So, it was difficult to get through. Yeah, it was not fun to hear about, not fun to watch, but I presume it'll be fun to watch for millions of other people."
Brett attended Thursday's event with his twin brother and his girlfriend Marie-Lou Nurk, as well as Selling Sunset costar Amanza Smith, to celebrate the launch of the 1060 App, a new app designed for the real estate industry that provides an endless stream of the world's most amazing houses and apartments through short digital videos, according to the company's website.
A source confirmed to PEOPLE in August that Quinn, 34, will not return for seasons 6 and 7 of the hit Netflix series. Production for the upcoming seasons began this summer. TMZ was the first to report the news of Quinn's departure from the series.
Since it first premiered in 2019, Quinn has been a staple on Selling Sunset, which follows the Oppenheim Group real estate firm as they sell some of the most exclusive luxury homes in Los Angeles.
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Over five seasons, fans watched as Quinn not only sold real estate, but was also involved in drama with all of her costars. In an explosive season 5 conflict, Emma Hernan claimed Quinn bribed a client with $5,000 to quit working with her. Quinn vehemently denied the accusation.
"I terminated my contract when the brokerage launched," Quinn said. "I had to make a business decision that was for me, so I had to terminate the contract so I could move it over to my brokerage."