It was just a chance encounter on a downtown street — but she was instantly enamored.
“I’ve seen you on TV. You’re so cute,” said the woman who would later accuse Greg Kelly of rape, according to a law-enforcement source.
The brunette crossed paths with the handsome “Good Day New York” host two days before the alleged attack.
“She stopped him,” the source said. “She told him she was star-struck.”
What followed was about 48 hours of marathon sexting ahead of their Saturday-night date at the South Street Seaport.
“The texts were explicit,” said the source. “They were sexual. They talked about what they wanted to do to each other.
“It was two days of foreplay.”
Kelly and the 29-year-old paralegal — an aspiring model and actress whose name is being withheld by The Post — also spoke by phone and exchanged e-mails before meeting up, the source said.
On the night of their date, the woman’s boyfriend was at home, so she concocted an excuse to get out on her own.
“She lied to the boyfriend to meet Greg that night. She said, ‘I’m going out with a girlfriend,’ ” said the source.
They ordered drinks at a seaport bar, running up a tab that another source has described as “laughably low” — and then headed to the woman’s lower-Manhattan law firm.
They had sex there — right in her boss’s office, the source said.
If the woman was upset about the randy romp, she gave no clue in follow-up messages to Kelly, the son of Police Commissioner Ray Kelly, the source said.
“They continued to text,” the source said. “Part of it was about arranging another date.”
In total, there were 17 text messages between the two.
“You don’t text your rapist — other than to say, ‘You’re awful,’ ” the source said.
But the woman, whose brother is an NYPD sergeant assigned to the crime-scene unit, insisted she was sexually assaulted by Greg Kelly.
She claims she’d had so much to drink that she was incapable of rejecting Kelly’s advances.
The source said that DA investigators are aggressively looking into every possible piece of corroborating evidence, including videotape from the woman’s office building and witnesses who might have seen the couple coming in or leaving.
“Did they leave together?” the source asked. “Did she use a swipe card? Did a guard see them? These are things you want to know. There’s a difference between being drunk and being physically helpless. Nobody had to carry her.”
Probers are also looking for anyone who might have spotted the two at the bar or on the street.
“What do the phone records say? How many drinks did they have?” the source said.
The source reported that the woman has been forthcoming with prosecutors and never attempted to hide anything. “She’s very candid,” the source said.
The woman told prosecutors that Kelly, a single former Marine, got her pregnant and that she underwent an abortion.
The source believes the case will hinge on the accuser’s motivation: “What drives someone who’s making a delayed report?”
The accuser didn’t come forward until last Tuesday, three months after the affair.
Before she made her complaint, her boyfriend confronted Ray Kelly at a public function and told the commissioner that Greg “ruined my girlfriend’s life.”
The top cop told him to write it in a letter, which he apparently never did.
The NYPD immediately handed the investigation over to the Manhattan district attorney because of the inherent conflict of interest.
The case is being handled by Martha Bashford, an experienced and venerable sex-crimes prosecutor who founded a special unit at the Manhattan District Attorney’s Office that uses DNA to solve rape cases.
Bashford is highly respected at the office run by DA Cy Vance Jr.
“Martha has done this for 30 years,” said a source who knows her. “She’ll leave no stone unturned.”
One defense lawyer said the e-mails prior to the liaison are a problem for the prosecutors.
“I think, in a case like this, if there’s a run-up to the encounter and there’s alcohol involved, that becomes a very difficult case to prove, but that doesn’t mean it shouldn’t be investigated thoroughly,” said Mark Bederow, a defense lawyer who used to work for the Manhattan DA’s Office.
Greg Kelly, meanwhile, has been keeping a low profile and hasn’t been seen in public since Thursday, when he took an indefinite leave of absence from “Good Day New York” on Fox 5.
The TV station is owned by The Post’s parent company, News Corp.
His grim-faced father declined to answer questions about the case during a promotion ceremony for police officers on Friday.