A jealous boyfriend threw a glass in his girlfriend's face after he became angry when she spoke to another man in a pub beer garden.
Former soldier John Gledhill, 30, caused the victim to need an operation after she suffered cuts to her face and hands in the attack outside the Ponte Tavern, Pontefract.
Leeds Crown Court heard Gledhill had met the woman on an online dating site months before the incident, on May 28 this year.
Robert Galley, prosecuting, said the couple quickly formed a relationship and moved in together but Gledhill had been "controlling" towards her.
Mr Galley said Gledhill swore at his partner after noticing another man looking at her when they were inside the pub.
The couple then went outside and Gledhill kissed his girlfriend and said everything was alright.
But he turned violent when the same man came outside and spoke to her.
The prosecutor said Gledhill threw his pint glass at her face from a distance of around three feet.
Three men in the beer garden managed to stop Gledhill from causing further injuries.
The victim suffered cuts to her nose, forehead and fingers. She needed an operation but has not been left with permanent injuries.
Gledhill, of Princess Avenue, South Elmsall, pleaded guilty to unlawful wounding.
He has previous convictions for assault.
Simon Alexander, mitigating, said Gledhill had served in Afghanistan during his time in the army.
Mr Alexander said the victim was now pregnant with Gledhill's child and it was hoped their relationship could continue.
Describing the attack, he said: "He accepts that the injuries were caused by alcohol and an element of jealousy towards the man who was hanging around the table and making his presence felt."
Gledhill was jailed for 14 months.