The 'We Can't Stop' hitmaker danced on stage with Robin Thicke in a flesh-coloured bikini during a rendition of his single 'Blurred Lines' at the event and her fiance is said to be 'embarrassed' by her antics, reported Radar online.
"Liam really does care about Miley, but her racy new look and sort of ghetto attitude isn't exactly what he signed up for. Her VMA performance absolutely mortified him and he couldn't be more embarrassed. He doesn't really see anything sexy about what she did on stage," a source said.
Their relationship could be coming to an end with the 'Hunger Games' actor growing disillusioned with her wild behaviour.
"It's pretty much over. He knows he can't stay with her when this is who she's become ... He doesn't want to babysit her anymore. He has to move on," the source said. Hemsworth's team are apparently pushing him to end their romance because they fear it will damage his career.
"It's not just Liam that Miley is pushing away... His entire team is urging him to part ways with her because she's nothing but negative for his reputation and career. Liam is a serious actor with a growing career, while Miley has just turned into a joke," it added.