A bar worker threatened a friend with a knife when a "tangled web" involving two couples exploded into anger, York Crown court heard.
Gavin Andrew Craven, 28, cancelled a lift home from the pub on February 9 from his former girlfriend Tara Brown because he wanted to spend time with his housemate Amanda Cussans, said Jessica Strange, prosecuting.
Craven and Ms Cussans had been drinking together that evening, and they had had sex after his relationship broke up and she had broken up with her former boyfriend Tom Swift.
But Ms Cussans also contacted Ms Brown, saying she had declined to go into the city centre with Craven that night because she had arranged to meet Mr Swift.
Ms Brown collected Ms Cussans from the pub and Craven, angry, walked home where Mr Swift was waiting. Craven went inside, fetched a knife and threatened to stab Mr Swift with it, the court heard.
Craven, of Whitley Close, Rawcliffe, pleaded guilty to having an offensive weapon in public and using threatening words and behaviour.
The Recorder of York, Judge Stephen Ashurst told Craven: "There is nothing new about people feeling bad or taking offence at a change of relationship, but you had no reason to take that knife."
He took into account the 15-feet between the two men when Craven made the knife threat.
He gave Craven a nine-month prison sentence suspended for 18 months on condition he did 18 months' supervision, a rehabilitation programme and 100 hours unpaid work.
For Craven, Neal Kutte described the events of that evening as a "tangled web". Craven had spent weeks drinking too heavily.
But he and Ms Brown were now back in a relationship and there were "no ongoing issues between them". He had stopped drinking since the night of the knife incident, had started counselling and was genuinely sorry for what had happened.