A Woman threw her then boyfriend's phone into a bath of hot water before their "toxic" 10-year relationship ended in violence, a court heard.
Carol Costello (35) admitted damaging the phone but was acquitted of assaulting her ex-partner, who suffered "gruesome" head injuries after the hotel room argument.
Costello hit David Boland on the head with a glass but insisted it was self-defence and that he attacked her first.
Judge John Hughes dismissed the assault charge, saying there was a conflict of evidence and he had a doubt in the absence of independent witnesses.
He said there had been "nil co-operation" from the hotel, the Kilford Arms in Kilkenny.
Costello, a supermarket sales assistant of Rathmines Avenue, Dublin 6, had denied assault.
Judge Hughes gave her the benefit of the Probation Act for criminal damage, which she admitted.
Dublin District Court heard the couple had spent Christmas 2018 in Kilkenny and returned to their hotel room early on December 27 after drinking throughout St Stephen's Day. They argued as Costello wanted access to Mr Boland's phone.
He alleged she smashed it off a table, ran into the bathroom and threw it into the tub which was full of hot water.
He said there was a struggle and he "put her on the floor" to calm her.
A staff member called to the room and left again.
Mr Boland said Costello went back to the bathroom and when he followed her, she turned and hit him on the head with a glass.
He insisted he never "laid a finger on her" except to hold her shoulders, and denied threatening, hitting or choking her.
Costello said she did not smash the phone off a table but did throw it into the bath to be "petty" and alleged Mr Boland became angry and slapped her on the face.
There was a struggle and Mr Boland put her to the floor, got on top of her and started choking her, she alleged.
She alleged that he "came at her" again and she grabbed the nearest thing to her - a pint glass - and struck him in self-defence.