Scroll down for video and a list of winners
Cosy: Taylor Swift, Ed Sheeran and Harry Styles pose for a photo with a male friend at Robin Thicke's MTV VMAs after-party
However, the former couple were carefully positioned apart, with their mutual friend Ed Sheeran and another friend standing between them.
Earlier that Sunday, Taylor appeared to take a pointed swipe at Harry while accepting the award for Best Female Video.
The 23-year-old singer won for I Knew You Were Trouble, a track widely understood to have been written with Styles in mind after she felt rejected by the 19-year-old British star following their first of two attempts at a relationship.
Back-handed compliment: Taylor Swift thanked Harry Styles as the inspiration for I Knew You Were Trouble in her speech after winning Best Female Video, on Sunday at the MTV VMAs
Cue polite clapping: Harry looks awkward as Taylor appears to reference him on-stage
Oh dear: Niall Horan and Louis Tomlinson seem to be smirking at Harry's expense, who doesn't know where to look
After receiving the astronaut trophy from Pharrell Williams and Daft Punk, Taylor appeared to use her acceptance speech to send a pointed message to her teenage ex-boyfriend.
She said: 'I want to thank the fans because I tweeted about this a lot, I really wanted this.'
She then added: 'I also want to thank the person who inspired this song because he knows exactly who he is, because now I've got one of these.' The camera immediately cut to Harry, who appeared awkwardly to chew gum.
Close encounter: Taylor passed Harry as she strolled up to receive her award, while Rihanna chatted and looked the other way
Pharrell matched the DJs' glamorous look in a glittering jacket as he beamed while presenting Swift with the award.
The winning moment: The 23-year-old singer was thrilled as she was announced the victor, while pal Selena Gomez sat by
Quite the presenters: Taylor was given the award by Daft Punk and Pharrell Williams
But it was not the only odd moment for Taylor regarding her ex on Sunday.
Styles' band One Direction were the presenters for Best Pop Video, and when the boys walked on stage the 22 singer appeared to mouth an obscenity: 'Shut the f*** up'.
It was unclear if the words actually left Taylor's mouth, but it was certainly consistent with her swipe at Harry later in the evening.
Controversial: Swift is thought to have mouth an obscenity when Styles hit the stage to present an award
Unimpressed: Taylor reacts as she watches her ex Harry accept Song Of The Summer with his bandmates
Meanwhile, Taylor was channelling Marilyn Monroe glamour with her hair done in delicate blonde curls.
Completing the country singer's old Hollywood '50s ensemble was a black gown featuring a plunging neckline.
Meanwhile, Taylor sent out a strong message to ex-boyfriend Harry at the Grammys earlier this year.
Straight face: Taylor fixes her eyes on Harry as One Direction accept their award for Song Of The Summer
Sharing a laugh: Taylor and Selena shared a private joke
In an apparent dig at her former British love, the singer adopted an English accent as she pretended to speak on her phone mid-performance during a rendition of We Are Never Ever Getting Back Together.
'I'm sorry, I'm busy opening the Grammys and we're never getting back together,' she quipped, seemingly mocking Styles.
The interlude punctuated an incredible performance by the singer, who parted from Harry in early January after a holiday to the British Virgin Islands went sour.
The gong: Swift won for Best Female Video
Old Hollywood glamour: The country singer seemed to channel Marilyn Munroe in a revealing black gown
By November, they had given their romance another try and spent New Year's together in New York City.
But just a few days later, they split after rowing on holiday in the Caribbean, with their romance lasting just two months.
Watch the VMAs on MTV UK on Monday night at 9pm.
Better times: Harry and Taylor pictured in New York near the end of their romance in February
MTV VIDEO MUSIC AWARDS 2013 WINNERS
Over the moon: Justin won four moonmen awards
Video Of The Year: Justin Timberlake, Mirrors
Best Female Video: Taylor Swift, I Knew You Were Trouble.
Best Male Video: Bruno Mars, Locked Out of Heaven
Best Pop Video: Selena Gomez, Come & Get It
Best Hip-Hop Video: Macklemore & Ryan Lewis featuring Ray Dalton, Can't Hold Us
Best Rock Video: Thirty Seconds to Mars, Up In the Air
Best Collaboration: Pink and Nate Ruess of Fun., Just Give Me a Reason
Best Video With A Social Message: Macklemore & Ryan Lewis featuring Mary Lambert, Same Love
Best Song Of The Summer: One Direction, Best Song Ever
Artist To Watch: Austin Mahone, What About Love
Michael Jackson Video Vanguard Award: Justin Timberlake
Best Direction: Justin Timberlake's Suit & Tie (director David Fincher)
Best Visual Effects: Capital Cities, Safe and Sound
Best Choreography: Bruno Mars, Treasure
Best Art Direction: Janelle Monae featuring Erykah Badu, Q.U.E.E.N.
Best Cinematography: Macklemore & Ryan Lewis featuring Ray Dalton, Can't Hold Us
Best Editing: Justin Timberlake, Mirrors
