The West Midlands Police officer was targetted by her jilted ex-boyfriend - a serving sergeant - when she started seeing another colleague in 2011.
When her besotted former partner found out about the new relationship he began to bombard her with messages and even asking her to marry him in a text.
The trio - who cannot be named for legal reasons - were referred to at the Birmingham Employment Tribunal on Monday as Officer's A, B and C.
The hearing was told how the female Officer A had been in an "intimate relationship" with Officer B for two years before she broke up with him when it turned sour in September 2011.
Heartbroken Officer B had even ended a seven-year relationship with another cop in order to be with Officer A, employment judges heard.
During that time she courted the affections of THREE other younger PCs by flirting with them over text messages before finally settling down with Officer C.
After hearing of his colleague's plans to move in with his new lover "desperate" Officer B then showered Officer A with 10 texts and phone calls over a 24-hour period between October 23 and October 24, 2011.
Despite ruling that the constable had "enjoyed the attention of male colleagues" the tribunal agreed Officer A had been sexually harassed in the work place by her jealous ex.
In a reserved judgement Judge Bryn Lloyd said: "The claimant cannot be blameless in the catalogue of events.
"Put starkly, she decided unilaterally to cast aside what had been a mutually flirtatious, intimate personal relationship with B, and perceive it as harassment.
"It was clear to the tribunal that the claimant had indeed derived much work-related benefit from her personal relationship with B.
"On one date, September 4, 2011, the claimant received affectionate text messages from three different male officers on her team.
"We believe the claimant enjoyed the attention of male colleagues.
"She was fully aware we think that not only B, but other young male colleagues liked her and were eager for her company and attention.
"He had ended his relationship with his long-term girlfriend so that he could be with the claimant; only to learn that she was now in a relationship with C.
"The claimant did nothing before the 24 hours or so from October 23 and 24 to disabuse B of the notion that they were de facto a couple; or at least were likely to become 'a couple.'
"But we believe that she always knew that would never happen and that was not her intention.
"The bombshell for B was the discovery during the week of October 2011 that she was in a serious relationship with C and that they intended to cohabit.
"By that time, because the balance of B's mind was disturbed by his realisation of the truth, he descended into a course of conduct that was tantamount to harassment, and it was harassment on the grounds of the claimant's sex.
"B's behaviour towards the claimant on 23/24 October, 2011, was not defensible. He engaged in discrimination during that period.
"We do not find that B is a bad person. He is not we think by instinct or demeanour the sort of man who routinely sexually harasses a woman in or out of the workplace."
The tribunal heard that officer B was given a warning for his behaviour by the force but the trio remain employed by the force in different areas.
They had previously all been based in the Black Country, West Mids., which covers the city of Wolverhampton and surrounding areas.
West Midlands Police yesterday (Tue) refused to comment on the case due to ongoing legal proceedings.