Fans of the "Gorgeous" singer spotted her inside the event.
Taylor Swift skipped out on the 2019 GRAMMYs to instead support her British boyfriend, Joe Alwyn, across the pond after the 2019 British Academy Film Awards in London on Sunday.
While Alwyn posed solo on the red carpet at a BAFTAs in a black suit and bow tie, fans spotted Swift inside an after-party with him following the event. The 29-year-old singer had her hair swept up for the occasion and was donning a light blue Stella McCartney dress.
It was a big night for Alwyn and his co-stars in The Favourite. The film earned the most BAFTA nominations this year, and ultimately proved to be the favorite, taking home seven awards in total, including Best Film.
Swift later posted to Instagram a photo of her posing in her gown, along with a message about how thrilled she was for The Favourite's big wins. "AHHHHH @thefavouritemovie just won seven @bafta awards !!!" she wrote. "Bout to go give some high fives - thanks @stellamccartney for this dressss."
One eyewitness tweeted that the couple was quite affectionate following the awards show.
Meanwhile, at the GRAMMYs in Los Angeles, Swift -- who already has 10 GRAMMY wins on 32 nominations -- is up for Best Pop Vocal Album for her album, Reputation.
ET learned last week that the 29-year-old singer would not be attending music's biggest night because she was staying in London while shooting the movie adaptation of Cats, which is set to premiere this December.
Though they've been seen out and about from time to time, Alwyn and Swift have yet to pose together on a red carpet and are careful not to share too much about their relationship. The 27-year-old actor did, however, chat with ET about whether he'd ever work with his famous girlfriend.
Here's what he had to say: