Assistant Chief Constable Rebekah Sutcliffe, 46, allegedly exposed her cleavage to Superintendent Sarah Jackson while at a party.
ACC Sutcliffe is said to have ranted at Supt Jackson claiming she would not be taken seriously as a policewoman, believing she had undergone a breast enhancement.
She told the younger officer she was a “laughing stock” and that male colleagues were discussing if she had taken a cosmetic procedure, the tribunal heard.
ACC Sutcliffe then allegedly pulled her dress down to expose her chest at the party in May at the Hilton Hotel in Manchester.
The tribunal heard she said: “Look at these – look at these! These are the breasts of someone who has had three children. I know they’re ugly but I don’t feel the need to pump myself with silicone to get self esteem.
But things took a turn for the worst when Sutcliffe drank four glasses of wine during the meal, the tribunal heard.
It is alleged that the dispute broke out between Sutcliffe and Supt Jackson at a public mezzanine bar on the first floor.
Supt Jackson’s statement said: “She exposed her left breast completely at me and was shouting at me saying: ‘Look at these, look at these!’”
Counsel for the hearing Fiona Barton QC said: “Supt Jackson was mortified embarrassed and ashamed but as she became more and more visibly upset and tried to defend herself, ACC Sutcliffe took hold of the front of her dress pulled it down and exposed her left breast.
“She opened up the police service and Greater Manchester Police to ridicule. She was a critical role model and was supposed to lead by example.”
The day after the alleged incidents Sutcliffe made repeated attempts to make amends with Supt Jackson by email and text.
Sutcliffe faces charges of failing to treat Supt Jackson with respect or courtesy and disreputable conduct.
The hearing continues.