Harold and Gertrude had been married for fifty years and played golf together every Saturday.
One day while out on the course, Harold said to Gertrude, "Honey, there has been something bothering me all these years that I'd like to get off my chest before I die. You remember when we were first married and I had that pretty young secretary working for me? Well, I had an affair with her. But it was only one time, that was many years ago and I have been faithful to you ever since."
Gertrude replied, "Harold, there is something bothering me which I need to tell you. Three years before I met you, I had a sex change operation."
Harold was visibly shaken and could only reply, "Honey, how could you have never told me this?...and all these years you've been hitting from the ladies tees!!"