Who didn’t love Julia Roberts in Pretty Woman? The movie turned her into a bonafide superstar, and apparently the actress didn’t get there on her own.

She was inspired by real ladies of night — if you catch our drift.

According to Barbara Marshall, widow of the film’s director Garry Marshall, Julia spent hours with prostitutes while researching the role of a hooker who gets a corporate high roller (Richard Gere) to fall in love with her.

“Garry would never visit me… because he was a hypochondriac and afraid of getting a disease,” Barbara, a nurse who was volunteering at a free clinic at the time, told Page Six. “But he asked if Julia could come and talk to some of the patients.”

“I recruited two young women who came to the clinic regularly, and I paid them $35 each to meet with Julia,” she added. “I went back to work, and about 20 minutes later, Julia yelled from the end of the hall, ‘Bye, Barbara. We’re going to take a drive. We’ll be back later.’”

That’s when Barbara apparently panicked and called Garry to say, “Your star just left with a group of girls, and I think they were heading to Hollywood Boulevard. I’m worried. What if she doesn’t come back?”

Of course, Julia did return safely. And all was well!