One never knows where your personal life starts when one is a top employee at such a big company as Boeing. Ex-CEO Harry Stonecipher, however, knows.

He was fired Monday, ten days after his affair with the fellow employee was disclosed. Stonecipher, 68, is married but has lived separately with his wife for some time. 48-year old Debra Peabody, his mistress, is Boeing’s vice president for operations and commercial activities assigned to the company’s Washington government-relations office in Arlington, Va. They first met in January, insiders say, and Stonecipher started calling Peabody but she did not return his calls.

Boeing justified its decision by the possible loss of reputation and the majority of the big corporate clients.

Boeing refused to name Stonecipher’s mistress, but BusinessWeek yesterday published Ms Peabody’s name. It said that the name had been provided by four separate unnamed senior executives.

Peabody was not fired and Boeing declined to comment on her involvement in the affair. She helps the board to probe the case.