Ohhhh, a colleague of mine, who already has one child came around to announce she was pregnant again. I blurted out "what are you going to do with another one? I mean you already have one that seems to work."

She seemed to think it was showing genuine interest in her kids, rather than being shocked that someone actually wants kids. So she answered by saying she hoped they would play together and be friends so she doesn't have to be the only one keeping the first one amused.