David Playle, 32, could hear the bones cracking as his boyfriend Dannii, 28, was set upon by a group of men early on Sunday morning.
The couple had been walking home from a party with a friend when someone yelled out "faggot" near the corner of Courtenay Place and Cambridge Terrace about 1.30am.
"We heard it and we were a bit shocked because you don't hear that kind of thing very often," Mr Playle said.
"We turned back and we were just like, 'Hey, what's going on?' - not in an abusive way or anything - and they were like, 'We're all good, sorry, we're just out having a good night."'
The couple and their friend continued walking, thinking the incident was over.
But moments later, a group of several men came running up behind them and pulled their friend aside, punching him in the face.
Mr Playle said his boyfriend tried to intervene but he was "tossed around" by the group, who punched him in the face until he fell to the ground.
"I could hear the punches, and I heard the cracks when his jaw fractured," Mr Playle said.
"It happened so fast that I was in shock. I was just really, really upset."
Mr Playle chased the attackers to Waitangi Park, where a police patrol was parked. Two men were later arrested and charged.
Mr Playle described his partner as a peaceful person.
"He's just a lovely guy and he would never get into a confrontation. Knowing him, he would have just been trying to say to them, 'Stop, please just stop'."
Dannii, who wanted to be known by his first name only, said he had no doubt it was a homophobic attack.
He had not encountered such behaviour since he was a teenager in a farming town.
"It's the year 2013. It's a bit ridiculous," he said.
"It's a horrible thing to happen - gay, straight or whatever. I try not to get angry about it, because anger is what started it."
Dannii was treated at hospital for a fractured jaw and facial injuries. He was recovering at home but was still in pain.
A Wellington police spokesman said two 20-year-old men were arrested about 2am on Sunday.
They will appear in Wellington District Court on Friday charged with fighting in a public place.
Officers had spoken to two witnesses but were yet to interview Dannii, who they were hoping to speak to on Friday.
Police would also review camera footage of the incident.
"At this stage it's probably too early to say whether this was a malicious attack," the spokesman said.
Further charges could follow after police had spoken to Dannii and reviewed the footage.
