She told BBC Radio 2’s Sounds Of The 90s With Fearne Cotton that they were “so sassy” towards the man in the backstage incident at the Brit Awards.
“It was our Pretty Woman moment,” the singer said.
“Do you remember when Julia Roberts is in that shop in Pretty Woman and she goes, ‘Big mistake!’
“I think when you’re in a pack you feel a little more confident.
“We went up to him… and went, ‘You turned us down, big mistake’.
“We were so sassy with it.”
The incident took place at the 1997 Brit Awards, she said.
Horner also said that her and Melanie C tried to storm the stage at a Blur concert in London after going backstage.
“We were thinking, yeah, maybe we can just jump on stage and, you know, dance along, mosh along with Damon Albarn.
“We were probably about 10 centimetres away from the spotlight, sharing it with Damon Albarn.
“Then suddenly this big arm scoops the pair of us.
“We were dragged into the shadows by a security guard going, ‘I don’t think so’.”
Melanie C said they had agreed to do it as a dare if the next song was their hit Girls And Boys, which it was.
“We saw Damon at the after party and he said if he had known it was us, he would have let us stay on,” she said.
“So it was a missed opportunity.”