I'm waiting to use the line. I work in a lab and we do some of work that I consider not safe for pregnant women, but if perfectly safe. One type of experiment involves working with co-irker and I hate it. I don't like working with him as he gets the timing wrong, thinks he's always right, and when he contaminated an area blamed someone higher up. Yeah, that was smart. Needless to say he cleaned up the area and made me less excited about working with him. Higher up put him in his place

So with all the work going on and co-irker claiming to be really good at everything I'm not available to help on one experiment and figured he could cover it with our boss or recruit someone else. And he's just back from a long vacation. First words out of co-irker's mouth, "Is she pregnant?" Boss just said he wasn't discussing that and told me later about the conversation.
So what do I say when co-irker brings it up? Evil me wants to give him the look of death and say "Are you saying that I'm fat?" I"d love to use "What an interesting assumption?" But mostly I'm worried that he's telling his friends in other divisions what he thinks and that he may bring it up in front of my coworkers. He won't see it as rude. Remember he forgets to cover his mouth when coughing or sneezing so my personal news would not be off limits to him.