Cast your mind back to 2007.
If you were anything like us, you were probably strutting around in your low-rise jeans, donning that weird pouf hairstyle thing that was super cool and watching with your mouth agape while Britney Spears experienced her famous meltdown, shaving her head and bashing a paparazzo's car with an umbrella.
At the same time, Gossip Girl had just premiered on our TV screens, creating a cultural phenomenon that catapulted the Upper East Side and Blair Waldorf's cute headbands into the lexicon of teenage girls around the world.
And of course, we couldn't get enough of the juicy love story between the show's two main characters, Brooklyn "lonely boy" Dan Humphrey and glamazon Serena van der Woodsen.
But did you know that the actors who played these two iconic characters - Penn Badgley and Blake Lively - actually dated in real life?
The actors fell in love and were together for the first three seasons of the show, from 2007 to 2010, mirroring the way their characters Serena and Dan dated during those same years.
But it took years for the couple to go public with their romance, coyly denying dating rumours and dodging questions about each other.
In fact in 2008, a year after the pair started dating, Blake flat-out denied she and Penn were an item.
"Everybody always tries to dig into your personal life or create things that aren't there ... It's silly," she told People magazine when asked about the rumours.
"Any male friend is obviously a 'romance alert' [for the media], but I've always been friends with boys my whole life."
That same year, Penn was asked about his relationship with Blake - and he was gushing in his praise of the gorgeous blonde - though he still denied they were officially together.
"I think she's incredible," Penn told People.
"She's an amazing person and she's beautiful – so there's not a lot to dislike."
But just a few months later, the pair were ousted, after they were photographed kissing while on vacation in Cancun.
The secret was out!
It turns out, there was actually a very simple reason why Blake and Penn tried to keep their relationship a secret - they were afraid their bosses on Gossip Girl would be upset they had mixed business and pleasures.
"I remember there was one point where we were just afraid of how our personal lives overlapping our work life could be perceived by our bosses," Blake told Vanity Fair in 2017 to celebrate the show's 10-year anniversary.
"[But then] we were like, 'Oh no, that's exactly what they want.' They wanted us all to date. They wanted us all to wear the same clothes that we're wearing on the show. They wanted that, because then it fed their whole narrative. People could buy into this world."
The art-meets-life narrative was one that helped fuel the insane global success of the show.
"At the time, I was wearing the same clothes and doing fashion shoots, and dating the same person that my character was dating ... and because of that, what people were projecting onto me was that I was Serena," Blake said.
"We look the same, and we acted the same as far as they could tell, because I wasn't doing anything but that show. If [Penn and I] were photographed walking down the street, they didn't know if it was a paparazzi shot or if it was a shot from the show."
Blake added: "At the time, what was heightened was, wow, it all looks similar from the outside, but it's so different on the inside."
Even after they broke up, the pair were the ultimate professionals. Despite the fact that their characters were still in an off-again/on-again relationship, they didn't let any awkwardness get in the way of their jobs.
"We were constantly professional to be honest and we should both pat ourselves on the back because anything is complicated in that way... and we handled it," Penn revealed in 2015.
In fact, they acted so normal that even their bosses didn't know they had split.
"The shocking thing was, I found out on the set of the season 2 finale that Blake and Penn had broken up months before," co-producer and writer Joshua Safran told Vanity Fair.
"They kept the breakup hidden from the crew, which you could never do now. I don't even know how they did it. They kept it from everybody which is a testament to how good they are as actors. Because they did not want their personal drama to relate to the show."
Even Blake and Penn's co-star Chace Crawford, who played the handsome Nate Archibald, said their breakup never caused any drama on set.
"During your time on Gossip Girl, Chace, did Blake Lively and Penn Badgley's real-life romance, relationship and breakup cause drama amongst the cast?" TV host Andy Cohen asked Chace on Watch What Happens Live in August.
"Not at all, not in the least," Chace replied. "The most mature people in the world, yeah."
WATCH BELOW: This is what the cast of Gossip Girl looks like now! Story continues after video.
The only bad thing about having to act opposite your ex? The kissing scenes.
During an appearance on Watch What Happens Live in 2015, Penn was asked to rank the best and worst onscreen kisses he's ever had.
Ever the gentleman, Penn was diplomatic in his response.
"I'd say best ... I'll say it was Blake, because we actually had a relationship at the time," Penn said.
But when asked who was the worst, he jokingly quipped: "Maybe Blake after we broke up!"
It's clearly all water under the bridge now, with both Penn and Blake happily married in new relationships.
Blake married Deadpool star Ryan Reynolds in 2012 - they have three children together - and Penn is married to singer and doula Domino Kirke, with whom he co-parents her stepson.
- PuzzlesThe Australian Women's Weekly February Issue Online Entry
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