The 29-year-old singer arrived at 8:55 p.m. to the Moschino show, almost an hour past the event's scheduled start time. Photographers who had been waiting for Perry to arrive booed her as she posed for photos on the runway, further delaying the show.
Perry can be heard to sassily say "Shut the [expletive] up" in a video of the incident, but a source tells Us Magazine that the star seemed "upset" during the show and was "pretty shaken up" as she posed with fans afterwards.
One insider defended Perry and said "that was the time she was told to come." Another commented on the hectic nature of fashion week, and said Perry was "just getting around the hustle and bustle" of the events.
Moschino designer Jeremy Scott did not seem upset by Perry's late appearance. After the show, he tweeted his love for Perry and Rita Ora (who also showed up late to the show) that included a picture of the three on his Instagram.
Pregnant Mila Kunis wins 'Best Villain' at MTV Movie Awards
Biologists detail four new deep-sea 'killer sponges'