Taylor appeared to mouth the words "shut the f**k up" as the band collected the Song of the Summer award on Saturday, before later dedicating her own Best Female Video trophy, for 'I Knew You Were Trouble', to the band's Harry Styles, whom she previously dated and admits she wrote the song about.
Her antics have seen the rest of One Direction jump to Harry's defence, with Liam Payne saying: "I just thought it was a bit not needed. I mean, you just won an award, it's like, concentrate on yourself ... Hashtag get over it."
When asked if he thought Taylor's reaction was "lame", he added: "Yeah, We were a bit confused."
Despite Taylor's comments at the ceremony in New York, she and Harry, 19, were later pictured together at Robin Thicke's afterparty as part of a group, although they stood with mutual friend Ed Sheeran and another person between them.
Earlier on in the evening, Harry - who dated Taylor for just over two months between December 2012 and this February - had nervously chewed gum as Taylor, 23, dedicated her award to him, and did his best not to betray any emotion as the camera panned over to get his reaction.
He has previously said he doesn't regret dating the star because she wrote a song about him.
He explained: "It would be hypocritical for me to say she couldn't do it because everybody writes songs based on personal experience. I can't say I'd have dated someone less famous to avoid it.
"You like people for who they are, so I couldn't say I want to date someone less famous because of the hassle. You like who you like."