I have a tummy pooch and been asked lots of times.Since I am fixed, I just politely tell them so and then they ask, Don't you want more? I say sure I do, but we almost died bringing her into the world, so NO!!
But I did it someone else too-- It was after christmas and I saw a lady looking like she's 7 months along. I politely asked her if she was and she said no. Too many Christmas goodies, said she was going on a diet.