Incredibly, the paparazzo counters her plea, arguing that she hasn't provided him with a good enough photo opportunity yet.
"I lost my whole morning, and I didn't get no photos," he tells her.
"That's not my fault! Please leave me alone. It's the weekend, sir, please."
Captioning the video, Duff explains that the photographer had followed her from her son's soccer game to her sister's house, where he "basically parked in her driveway to get photos".
"I politely asked him to let me be and he continues to follow and stalk me down like pray [sic] for hours now. This is not OK. I am 9 months pregnant. When people say that's what you get for signing up to be a celebrity it honestly makes me sick. This is every day of every month and it's simply not OK. If a non 'celeb' (I'm sorry to use that word) was dealing with this, the law would be involved," she writes.