"I'm not paying that ******* bitch anything," Dey said.
Despite Dey's lack of any previous sexual convictions, Judge Michael Crosbie sentenced him to eight months' imprisonment.
"You lack any feeling towards what you did to this person," he said.
On the afternoon of August 26, Dey and the victim had just finished a friendly chat over a cup of tea at his South Dunedin home.
The defendant walked behind her to show her to the front door when he made the off-hand comment: "Hope you don't mind if I help myself."
Dey reached around the woman's back and gripped her breast.
The victim knocked his arm away, kicked him in the shin and hurriedly left the house.
When police spoke to Dey, he called it "an accident" and said he had been drinking all weekend.
Counsel John Westgate said his client could not remember the incident.
"It was an opportunistic, stupid thing to do," he said.
"He doesn't deserve to go to prison for a bad attitude."
But Judge Crosbie disagreed, as did Probation which said it had no confidence Dey would comply with a community-based sentence.
The victim told the court the incident had left her with "a lot of anger" and it had affected her relationship with her son.
The judge ordered Dey to pay the woman $1000.