Both Mayor Bill de Blasio and Gov. Andrew Cuomo were scheduled to speak at the New York delegation breakfast on Thursday morning.

What could go wrong, right?

The mayor, who is locked in an intense public feud with Cuomo, left the delegation breakfast shortly after the governor concluded his 25 minutes of opening remarks.

Buffalo Mayor Byron Brown told the delegation de Blasio was due to moderate a panel discussion elsewhere in Philadelphia and had to leave. His public schedule released by his office on Wednesday night showed the mayor would attend a panel discussion clled “City Solutions: Income Inequality” at 9:45 a.m.

The breakfast was scheduled to begin at 8:30 a.m., but speakers did not take the stage until around 9 a.m. Both the mayor and governor had released schedules advising they would speak at the same time.

It was de Blasio’s first and only appearance at the breakfast delegation this week while he is in Philadelphia for the Democratic National Convention.

Cuomo spoke first at the breakfast, followed by speeches and awards given to outgoing Rep. Charlie Rangel and Senate Minority Leader Andrea Stewart-Cousins.

Cuomo and de Blasio sat at separate tables during the breakfast, with the governor flanked by Rangel and his daughter, Cara. The mayor sat next to Comptroller Tom DiNapoli, whose office has released audits and reports critical of Cuomo’s handling of the state’s finances and economic development spending.