Then, "the applicant [Mr Omari] sought return of the gifts which included an engagement ring, on the basis that the condition on which they had been given did not eventuate. These were not returned."
Mr Omari went to the tribunal to seek the "monetary value of the gifts with interest".
Ms Yassine argued that Mr Omari had made a deal with her father that he would move to Melbourne from Canberra.
"After that he showed no interest in doing so and said that he was not going to. He also did not inspect wedding venues with the respondent. As a result of these issues the engagement was called off," the tribunal heard.
Senior ACAT member Graeme Lunney dismissed Mr Omari's application, meaning Ms Yassine is able to keep the ring and gifts.
"In my view there was not a unilateral withdrawal by one party in breach of a prior promise, but a recognition by two people that their relationship had reached a tipping point, and in the absence of any further action was over," Mr Lunney said.
"Consequently, in my view there was no 'breach' that occurred in the ACT which would give this Tribunal jurisdiction in the proceedings brought by the applicant.
"It was mutual recognition of an unhappy state of affairs that was beyond repair. In those circumstances the Tribunal lacks jurisdiction to adjudicate the dispute," he said.
While there is little legal precedent for cases like this, the Family Law Court can step in and intervene during a breakup, but only if the couple has been living together for at least two years.
The fate of an engagement ring depends on whether the court classifies it as a gift or an investment piece, says Slater and Gordon's head of family law Heather McKinnon.
"You don't go to court and pay $20,000 to $30,000 in lawyer's fees over a $5000 ring. You do it if it's of significant value," Ms McKinnon said.
"Usually it's with arranged marriages where big money changes hands, so these relationships are more likely to give rise to disputes.
"Often people go overseas to get the diamond and bring it back to Australia to get the ring fitted, so then it rises in value considerably," she said.
If the ring is large and expensive enough to be classified an investment, it is treated like a car, house or shares and the cost is divided between the couple, like any other asset.
"But if it's an average engagement ring it stays where it was given," Ms McKinnon said.
News.com.au has contacted Mr Omari and Mr Yassine for comment.