Hilary Duff makes rare admission about filming NSFW threesome scene in Gossip Girl

Hilary Duff has opened up about the 'most memorable part' of her role in legendary series Gossip Girl.

The 38-year-old has played some iconic roles throughout her acting career, particularly when in comes to classic 2000s rom-com movies and binge-worthy TV series.

From Lizzy Maguire to A Cinderella Story, Duff even made a surprise cameo in teen drama Gossip Girl, appearing alongside stars such as Leighton Meester, Blake Lively, and Penn Badgley.

Duff pops up in the series in season three taking on the role of Olivia Burke, a famous actor who falls for Badgley's character of Dan Humphrey.

During an interview with Harper's BAZAAR, Duff revealed what the 'most memorable part of playing Olivia Burke on Gossip Girl' was.

And the most devoted Upper East Siders among us can probably already guess which part of Duff's role stands out the most.

"Probably the threesome was the most standout moment," Duff answered, before diving in deeper.

Hilary Duff's character Olivia Burke is involved in a threesome (The CW)

Indeed, Duff's character Olivia ends up in a bit of a love triangle with Dan and his best friend (but also on-off love interest) Vanessa Abrahms (Jessica Szohr).

Olivia first enters the social scene of the Upper East Side as Vanessa's roommate.

Toying the line between movie star and just trying to be a teenager and fit in, Olivia becomes swept up in the drama and ends up romantically entwined with Dan after meeting him through Vanessa.

And who should go and suggest the three try hooking up altogether? Why, Olivia of course.

Duff admitted: "I remember being like, 'Ooo my mom's going to call me after this one'."

Duff has played a plethora of other iconic roles since - from Kelsey Peters in the comedyYounger and as Sophie in How I Met Your Father.

Despite this and how Duff's appearance in Gossip Girl was over 15 years ago, she revealed she still gets recognised from it to this day.

Duff's character is romantically linked to Penn Badgley's in the series (James Devaney/WireImage)

The star revealed she was in Paris 'not too long ago' and had to go up to a lady who worked at the airline after losing her bag.

Upon approaching her, the airline lady said: "Are you on Gossip Girl?"

"Yes. Love that's how you know me," Duff joked.

Well, hopefully next time she's recognised it's because of her recently released sixth studio album titled luck... or something.

Duff also has an upcoming docuseries which dives into her return to music after a 10-year hiatus.