Tulsa police were called to the Bank of America at East 31st Street and South 108th East Avenue just before 9 a.m. on a call of shots fired.
They found a man who had been shot in an apparent domestic incident outside the bank.
Police say the victim was meeting his ex-girlfriend in the bank parking lot. As the two were talking, the woman's current boyfriend walked up and shot the ex once in the leg.
The couple fled the scene in a maroon vehicle. The wounded man was taken to a local hospital in serious condition, according to EMSA.
Police are searching for the shooter.