A photo from the alleged incident has been blown up to poster size, but David Mueller claims it proves his innocence.
Taylor Swift's mom says that she was devastated when her daughter told her she had been groped backstage during a 2013 meet-and-greet.
Andrea Swift, who took the stand Wednesday spoke about the heartbreaking moment when her daughter told her, "Mom, a guy grabbed my butt."
Read: As Taylor Swift Heads to Court, See the Photo She Says Proves DJ Groped Her
She added that her superstar daughter "was really shaken and humiliated and horribly embarrassed because he grabbed her bare butt."
The incident made Andrea Swift sick to her stomach.
"I wanted to vomit and cry at the same time,” she said.
She then broke down in tears as she pointed an accusatory finger at former DJ David Mueller, saying, "He sexually assaulted her. That guy!"
The Grammy-winning singer’s mom testified after Mueller claimed Swift was "cold and standoffish" when he met her backstage for a photo op at a concert in 2013.
As he moved in to take a photo, he testified that he “came into contact with part of her body. Our hands touched and our arms touched. I felt what appeared to be a ribcage or ribs."
But he says he never touched her rear end, which is what has long claimed.
As Mueller testified, Swift sat right in front of the witness box, looking agitated. She turned to her lawyer with an expression of disbelief and appeared to mouth, “That's not true" and, "Wow!"
One photo of the incident, obtained by TMZ, is emerging as the key piece of evidence for both sides.
Her legal team has blown it up to poster size. They were seen carrying the giant photo into court Wednesday.
The DJ’s attorney says the photo actually proves his innocence by pointing out that if he had lifted the singer’s skirt, it would be hiked up and it's clearly not, at least in the photo.
Read: Bad Blood: Taylor Swift Groping Lawsuit Reveals Moment Ex-DJ 'Put His Hands Up My Dress'
Mueller testifiedSwift may have been groped not by him but by his boss. He testified the radio station's former program director told him he put his hand on the “Bad Blood” singer’s backside when they hugged each other in greeting.
"Taylor must wear bicycle shorts under her outfit,” the guy supposedly remarked.
The former program director says none of this ever happened.
Watch: Wildest Dreams: 7-Year-Old Does an Uncanny Taylor Swift Impression
