A woman watched as her partner was left with "blood pouring" from injuries after he was dragged down a road by her estranged husband's car, a court heard.
Vicky Spiller, 35, told Newport Crown Court she was walking home with Karl Davies, 40, when Ian Spiller accelerated towards them and hit him.
Mr Spiller, 36, from Bridgend, denies dangerous driving and causing serious injury by dangerous driving.
Mr Davies suffered a fractured skull and was knocked unconscious.
Mrs Spiller told the jury her estranged husband drove towards them as they walked through Laleston, Bridgend, and hit Mr Davies deliberately.
"He carried on driving and pushed him into the trees," she said.
"Karl fell backwards as the car was pushing him into the bushes."
The court heard Mr Spiller, a Liberal Democrat councillor for Laleston community council who had previously campaigned for safer roads in the village, was jealous of his estranged wife's new relationship.
He and his wife of 10 years were separated but still lived in the same house with their two children.
Mrs Spiller told the jury her relationship with her husband had been over at the time of the incident in February 2017.
She said: "The car reversed back down the road.
"I saw the car speeding away with Karl attached to the window by his hands. It was just speeding up and up and up.
"He got dragged down to his side then he got dragged down the road."
Prosecutor Christopher Rees told the court: "Spiller deliberately mounted the pavement to drive at Mr Davies, the man he had just found out was having an affair with his wife."
Mr Spiller was in the car with his sister-in-law and contends he only reversed to get away from Mr Davies because he had put his hands around her neck.
The trial continues.