Off screen, Christine Quinn has had to quash disgusting rumors as Selling Sunset casts her back into the spotlight.

Season 4 premiered last week, introducing Emma Hernan to the cast.

She and Christine share unexpected history: a mutual ex, who went unnamed on the show.

Now, we know the name of the man who caused such a stir on the ever-dramatic Netflix series.

Us Weekly reports that the mystery man is Peter Cornell.

Peter is a fellow realtor.

He is also the director of The Oppenheim Group's sports and entertainment division.

Peter Cornell is a Loyola Marymoun University alum.

He is something of a professional legacy, because he is a third generation real estate agent.

Before Peter got into selling real estate, he was a professional basketball player.

Yes, professional -- Peter played in the NBA with the Lakers.

He went on to play for multiple overseas teams.

After a decade spent playing the sport, Peter retired from basketball in 2009.

For more than six years, he has been making a name for himself at the Oppenheim Group's West Hollywood offices.

Peter has actually appeared on reality television before.

In 2015, viewers of Million Dollar Listing Los Angeles may have seen him on their screens.

Peter's real estate client list includes recognizable names like Kris Humphries.

In fact, upon retiring from playing sports, he took up work as a player agent.

That role allowed him to negotiate on behalf of active players, including prominent members of the NBA.

As Selling Sunset viewers may recall, Christine took time off to have her baby.

During that time, Emma Hernan was brought onto the show.

Emma is new to the series, but not to The Oppenheim Group -- where she has worked for years.

Emma wasn't there to replace Christine, but she did take on some of her workload while she was on maternity leave.

Sometimes, people can be territorial about their work. It happens.

But Christine and Emma's issues go back further than that.

Christine and Emma have a mutual ex, but it's not the kind of thing that they'd bond over.

Why? 

Because he was dating them both at teh same time.

Apparently, several years ago, Peter was dating both Christine and Emma.

According to Christine, he proposed to her months before he proposed to Emma.

Neither woman knew about the other until they one day came face-to-face while Emma was out with Peter.

That was also how the two women met.

Apparently, Emma and Peter were leaving the gym when Christine showed up, having spotted them.

Or, as she put it, she "caught" them "red-handed."

At that point, Christine must have simply assumed that Peter was (allegedly) cheating on her.

It was only Emma's indignant reply that he was her boyfriend that helped them both realize what had happened.

That sounds more awkward than we can imagine.

There were a lot of hurt feelings involved.

While neither woman was at fault, it's no surprise that there was drama.

You don't usually score a successful reality TV role if you're a master of handling situations like a mature adult.