A court heard Todd Morgan attacked the victim outside his home in Pontefract when he turned up at the property with a gang of ten men.
Andrew Espley, prosecuting, said violence took place on Friday October 13 this year after the victim was initially contacted by mobile phone.
Mr Espley said the person who made the call threatened to “date rape” the victim’s sister.
Other offensive remarks were also made.
Leeds Crown Court heard the victim then told the caller: “Why don’t you come around and say that to my face?”
A short time later four cars pulled up in the street and ten men gathered outside the house.
The prosecutor said the victim’s mother initially confronted the group but was pushed out of the way.
The teenager then approched the group and Morgan punched him once to the face, knocking him the ground.
The court heard the victim struck his head on a tumble dryer as he fell after the blow.
The victim suffered a break to his upper jaw. Mr Espley said: “It was a gang attack and the defendant played a leading role.”
Morgan was on bail at the time of the incident after being arrested for an attack on another man on June 10.
Morgan, of Market Street, Featherstone, pleaded guilty to two offences of assault occasioning actual bodily harm.
Giles Grant, mitigating, said Morgan accepted responsibility for what he had done and had spent more than two months in custody since the second attack.
He said Morgan had been struggling to cope with breaking up with his partner at the time of the offences.