Overheat

In order to get revenge on his ex-boyfriend, Ha-Neul starts seeing his ex’s-boyfriend's younger brother, Hyeon-Seong. As a co-pilot, Hyeon-Seong meets frequently with Ha-Neul, who runs a flower shop nearby the airport. Then one day, Ha-Neul receives a call from his ex-boyfriend.

(Source: MrBlue, translated)