Open Mouth, Insert Foot

About 14 years ago, my sister started a new job. During her first week on the job, I met her at work for lunch. As I climbed the steps to the 3rd floor, I heard a door open and recognized my sister's voice. She was speaking to her "new" supervisor as I approached the final 3 steps. My sister looked at me, smiled, and introduced me to her supervisor, Nancy. The usual formalities took place. She was very friendly. Then I thought I would add a little more and show my sincere excitement for Nancy. I looked her straight in the face and asked, "When are you due?" Well, Nancy looked me straight in the face and replied, "I am not pregnant." I didn't think anything of it and continued, "Oh! Congratulations! Did you have a boy or a girl?" Nancy, whose eyes never left mine stated that she was not pregnant and has never been pregnant. Okay, at this time, I felt my sister's eyes staring at me and could feel the heat off her red face. You would think that I would have learned my lesson. But, instead ... open mouth, insert foot. I tried to explain why I thought that and mentioned the way the clothes fit her and how they were hanging made me think that. I kept rambling and finally apologized. How awful was that!?! My sister and I went to lunch and it took several years before I stopped in for lunch again.