By Aja Hoggatt
August 20, 2018 at 12:00 PM EDT

Watch the full episode of Couch Surfing streaming now on, or download the PeopleTV app on your favorite device.

What’s the worst thing that can happen when you’re cast as a character named ‘Perfect Girl’ in a romantic comedy with two of the world’s biggest stars? Let Emily Mortimer tell you.

Mortimer sat down with PeopleTV’s Couch Surfing host Lola Ogunnaike to take a look back at her experience filming Notting Hill. One of The Newsroom alum’s earliest film roles, Mortimer was cast as a minor love interest for Hugh Grant’s travel bookshop owner, William Thacker. However, the minor role became much more complicated when the film’s designated “perfect girl” showed up with hives due to an allergic reaction from a suit she found at a thrift store.

With hives and a face full of steroids to help combat the swelling and symptoms, Mortimer tried her best to make it through the scene. “It was a nightmare,” Mortimer declares.

“Every time I got nervous — which you do when you’re acting — I got hives and my face [became swollen], well, one side of it you can still see is sort of chipmunk-like,” she explains.

And the cast didn’t make it any easier for the young actress. “Everybody was really embarrassed. It was very awkward. It was like, who is this girl who’s come — she’s just got one scene and she’s making such a meal of it, and nobody would talk to me. It was weird.”

RELATED VIDEO: Bill Nighy is in love With Virginia Woolf, say ‘Bookshop’ costar Emily Mortimer

From working for Aaron Sorkin to a role in the much-anticipated Mary Poppins Returns, it seems things have worked out just fine for Mortimer.

Watch the full Couch Surfing video above for more.