TORONTO -- A young Toronto woman who vanished five years ago had an ongoing feud with her accused murderer's girlfriend, court heard on Friday.

Laura Babcock and Christina Noudga had both been sleeping with Dellen Millard in 2012, said Karoline Shirinian, 25, who described herself as a friend of both women.

"They would get along sometimes, but most of the time they didn't," she said.

Millard, 32, of Toronto, and Mark Smich, 30, of Oakville, Ont., are accused of killing Babcock in the summer of 2012 and incinerating her body. Both men have pleaded not guilty to first-degree murder charges.

The Crown contends the pair murdered the 23-year-old because she was the odd woman out in a love triangle with Millard and his then-girlfriend, Noudga.

Shirinian said she was friends with Babcock when the two women worked together at a toy store in Toronto, but they had a falling out the summer before Babcock disappeared.

Babcock and Noudga's troubles revolved around their feelings for Millard, she said. Then there was "an incident."

Shirinian and Noudga were having drinks on Feb. 12, 2012, she told court, when they "thought it would be funny to send (Babcock) a catty message for her birthday."

"Happy birthday. A year ago today was the first time I slept with Dellen," Noudga said in a text to Babcock, according to Shirinian, who smiled and briefly laughed on the stand.

Babcock's mother, Linda, bowed her head at the testimony.

"That's fine, I slept with him a couple of weeks ago," Babcock wrote back, Shirinian said.

Noudga was shocked and upset, she said.

In her opening statement earlier this week, Crown lawyer Jill Cameron told the jury about the bad blood between the two women. It became a problem that Millard promised to solve, she said.

"First I am going to hurt her. Then I'll make her leave," Millard allegedly said in a text to Noudga. "I will remove her from our lives."

Babcock disappeared in early July 2012. Her body has not been found.

Shirinian testified that she last spoke on the phone with Babcock on either June 30 or July 1. Babcock had been open and honest with her about being an escort and invited her to a ribfest in the city's west end. Babcock had plans to meet with some men that day to talk about starting a business.

She wanted to run her own escort agency, Shirinian said, who declined to go with Babcock that day.

Men would take Babcock out on dates, they'd drink and have fun, she said. Babcock would be paid $250 per hour.

"They would tip her with money and cocaine," Shirinian said.

The two also spoke about Babcock's ongoing mental health concerns. Court has heard that Babcock had told several people that she was trying to find out whatever ailed her mind. She told many friends she had anxiety, depression and borderline personality disorder, but was actively seeking treatment.

"As long as she was taking her medication, she was OK," Shirinian said. "When she began to feel she was OK, she would stop her medication and her symptoms would come back all at once."

Shirinian said Babcock's behaviour had changed from the previous summer.

"She'd get upset over things that were not a big deal and blow them out of proportion," she said. "That would start a feud. I'd seen it happen many times with many people. Happened to me, too."

Despite her mental health problems, Shirinian said Babcock was not suicidal.

"She was not going to kill herself, absolutely not," Shirinian said.

But another witness, who testified earlier on Friday, said Babcock was depressed and spoke about suicide in the weeks before she disappeared.

Jeff Wilson, a film and television producer, told court he met Babcock for the first time at a bar in Toronto's west end in the summer of 2012 where she asked to move in with him right away. She was having problems with a roommate in a Yorkville apartment, he said.

The arrangement lasted two weeks until he caved to pressure from friends and family who wanted her gone.

"It ended up in tears, she wasn't really ready to leave, had nowhere to go except back to that place in Yorkville," Wilson told court.

The next morning, she was either up before him or hadn't slept at all, and "had scratched herself to the point of bleeding," he said.

But a few days later, Wilson said he met with Babcock again and she told him she was happy.