The 'Delicate' singer wowed in a custom made pale blue Stella McCartney gown at the star-studded bash at London's Royal Albert Hall, where the 27-year-old actor's movie received seven gongs for Outstanding British Film, Leading Actress (Olivia Colman), Supporting Actress (Rachel Weisz), Original Screenplay (Deborah Davis and Tony McNamara), Costume Design (Sandy Powell), Production Design (Fiona Crombie and Alice Felton) and Make-Up & Hair (Nadia Stacey).
Sharing a picture of her stunning ensemble, which was completed with open toe heels, Taylor captioned the Instagram snap: ''AHHHHH @thefavouritemovie just won 7 @bafta awards !!! Bout to go give some high fives - thanks @stellamccartney for this dressss (sic)''
The 'Shake It Off' hitmaker was nominated for Best Pop Vocal Album for 'Reputation' at the Grammys, which took place on the same evening in Los Angeles - which saw Ariana Grande win the prize for 'Sweetener' - but she opted to accompany her partner to the British ceremony instead.
After the BAFTAs dinner, the pair were spotted leaving the British Vogue after-party at Annabel's Members' Club in Mayfair.
Meanwhile, the actor recently stated that his unwillingness to talk about his relationship with the 29-year-old pop megastar is ''normal''.
The 'Mary Queen of Scots' star has been dating the 'Look What You Made Me Do' singer for around two years and they both have been very guarded about their romance with the couple even avoiding being photographed together at the Golden Globe Awards last month.
Joe intends to stick his rule to not talk about Taylor, in interviews as he sees no justification as to why he should share details of his private life with strangers.
He said: ''I don't think more than anyone else. I don't think anyone you meet on the streets would just spill their guts out to you, therefore why should I? And then that is defined as being 'strangely private'. Fine. But I don't think it is. I think it's normal.''
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