The oldest gag in the book

I had my family over for dinner at my place the other day. Uncles, aunts, cousins and my granny. After dinner I asked for everyone's attention to say thanks for coming over, but as a joke I opened with:

Thank you all for coming. I just want to tell you that I'm three months pregnant. ha ha ha.

Everyone laughs...except my granny. Fallen jowls on a pearly green face. I continue filling in the dramatic story about keeping it and calling it Ralph regardless of its gender, completely unaware that my granny is decidedly not in on the joke.

A few minutes later I begin to notice the stunned horror paralyzing my grandmother and I quickly put her out of her misery!

"Just kidding" : the two most comforting words in the world.